METHOD FOR MANUFACTURING A SLAB OF ARTIFICIAL AGGLOMERATED STONE

Abstract

The present disclosure is related to a method for manufacturing slabs of artificial agglomerated stone comprising: depositing a first layer (1.1) of a first mixture (M.sub.1) onto a surface (2), wherein the first layer having a first thickness h.sub.1, creating at least one cavity (3), having a width w.sub.i and a length L.sub.i, in the first layer (1.1) of first mixture (M.sub.1), depositing a second mixture (M.sub.2) into the at least one cavity (3) of the first layer (1.1), forming a second layer (1.2) by depositing the first and second mixtures, and the second layer having a second thickness h.sub.2, compacting and hardening the second layer (1.2), wherein the method further comprises after step c) and before step d), inserting a first tool (5) at least partially into the second thickness h.sub.2 of the second layer (1.2), and actuating the first tool (5) wherein the first tool (5) is configured to stir the first wall portion (4.1) while not stirring the second wall portion (4.2).

Claims

1. A method for manufacturing a slab of artificial agglomerated stone comprising: a) depositing a first layer of a first mixture onto a surface, wherein the first layer having a first thickness h.sub.1, b) creating at least one cavity, having a width w.sub.i and a length L.sub.i, in the first layer, wherein the at least one cavity is defined by at least one cavity wall extending at least partially through the first thickness h.sub.1 of the first layer and comprising a first wall portion and a second wall portion in opposition through the at least one cavity width w.sub.i, c) depositing a second mixture into the at least one cavity of the first layer, forming a second layer by depositing the first mixture and second mixture, wherein the second layer having a second thickness h.sub.2, d) compacting and hardening the second layer, wherein the method further comprises after step c) and before step d), inserting a first tool at least partially into the second thickness h.sub.2 of the second layer, and actuating the first tool, wherein the first tool is configured to stir the first wall portion while not stirring the second wall portion.

2. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the first mixture and/or the second mixture comprises from 80 weight percent to 95 weight percent of an inorganic filler and from 5 weight percent to 20 weight percent of a hardenable binder.

3. The method for manufacturing slabs of artificial agglomerated stone according to claim 2, wherein the inorganic filler of the first mixture and/or the second mixture comprises from 5 weight percent to 50 weight percent of silicate glass, translucent synthetic silicate, or mixtures thereof.

4. The method for manufacturing slabs of artificial agglomerated stone according to claim 2, wherein the hardenable binder is a translucent organic resin.

5. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the first mixture and the second mixture have different composition or different inorganic filler particle size distribution or both.

6. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, further comprising in between steps b) and c), applying a first pigment composition to the at least one cavity wall of the at least one cavity.

7. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the at least one cavity is defined by: a width w.sub.i varying along the length L.sub.i of the at least one cavity, a width w.sub.i varying along the first thickness h.sub.1 of the first layer, or varying along both the length L.sub.i and the first thickness h.sub.1 of the first layer.

8. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the at least one cavity width w.sub.i ranges from 0.03 m-1 m.

9. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the at least one cavity length L.sub.i ranges from 0.01 m-3.5 m.

10. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein, during step b), the at least one cavity in the first layer is created by a template.

11. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, further comprising, during step b), creating the at least one cavity in the first layer by a wheel-shaped indenter.

12. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, further comprising, during step c), depositing a portion of the second mixture also outside of the at least one cavity.

13. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the first tool is rotatable around an axis X-X′ essentially parallel to the second thickness h.sub.2 of the second layer.

14. An artificial agglomerated stone slab comprising at least a first and a second mixtures defining chromatic effects, being manufactured according to the method of claim 1.

15. A plant for the manufacture of artificial agglomerated slabs comprising at least a first and a second mixtures defining chromatic effects, configured for application of the method of claim 1.

16. The method for manufacturing slabs of artificial agglomerated stone according to claim 2, wherein the hardenable binder is a translucent unsaturated polyester resin.

17. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the at least one cavity width w.sub.i ranges from 0.05 m-0.5 m.

18. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, wherein the at least one cavity length L.sub.i ranges from 0.1 m-3.3 m.

19. The method for manufacturing slabs of artificial agglomerated stone according to claim 1, further comprising, during step c), depositing a portion of the second mixture also outside of the at least one cavity proximal to the at least one cavity.

Description

DESCRIPTION OF THE DRAWINGS

[0155] These and other features and advantages of the disclosure will be seen more clearly from the following detailed description of embodiments provided only by way of illustrative and non-limiting example in reference to the attached drawings.

[0156] FIGS. 1a, 1b These figures show two embodiments of the shape of the cavity according to the disclosure.

[0157] FIG. 2 This figure shows a perspective view of a first layer of a first mixture comprising 3 cavities according to an embodiment of the disclosure.

[0158] FIG. 3 This figure shows a view from above according to the same embodiment shown in FIG. 2

[0159] FIG. 4 This figure shows a perspective view of a second layer according to an embodiment of the disclosure, comprising a combination of a first mixture and a second mixture deposited filling the 3 cavities of the first layer of FIG. 1.

[0160] FIG. 5 This figure shows a perspective view of a second layer according to an embodiment of the disclosure, where three cavity wall portions of each cavity of FIG. 1, are stirred.

[0161] FIG. 6 This figure shows a schematic front view of an embodiment of the first tool according to certain embodiments, configured to stir the second layer.

[0162] FIG. 7 This figure shows a schematic front view of an embodiment of a wheel-shaped indenter for creating a cavity in the first layer of first mixture according to certain embodiments.

DESCRIPTION

[0163] As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as method or product directly obtained from the method for manufacturing the product.

[0164] FIG. 1a and FIG. 1b depict two embodiments of cavity shapes that can be created. For example, FIG. 1a shows a specific embodiment of a cavity being shaped as an ellipse and FIG. 1b shows a specific embodiment of a cavity being circular. In both cases, these figures define the dimensions, length L.sub.i and width w.sub.i, and their positions in order to characterize each one of the cavities. In an elliptical shaped cavity, for example, the length L.sub.i is equal to the major axis of the cavity. In a circular shaped cavity, for example, the length L.sub.i is equal to one diameter of the cavity. Additionally, and also in both cases, the width w.sub.i is perpendicular to the length L.sub.i and the cavity width w.sub.i is variable up to a maximum w.sub.imax.

[0165] FIG. 2 shows an exemplary embodiment of a first layer (1.1) of a first mixture (M.sub.1) after performing a first a) and second b) step of the method for the manufacture of slabs of artificial agglomerated stone. Previously to the creation of the cavities 3 in the embodiment shown in FIG. 2, a first layer (1.1) of first mixture (M.sub.1) is deposited onto a surface (2), wherein the first layer (1.1) has a shape corresponding to the shape of the slab to be manufactured, and presents a first thickness h.sub.1. In embodiments, the first layer (1.1) has a first thickness h.sub.1 of 4.5 cm.

[0166] In some embodiments, the surface (2) is a sheet of Kraft paper, a sheet or film of a polymeric material, or a temporary mold.

[0167] As shown in FIG. 2, at least one cavity (3) is comprised in the first layer (1.1) of first mixture (M.sub.1). In some embodiments depicted in FIG. 2, the slab-shaped first layer (1.1) presents 3 different cavities (3) of different shapes.

[0168] The two cavities respectively on the left and right side of the first layer (1.1) shown in FIG. 2 might have a cavity width at its widest part of 15-30 cm, and might be created with a template (not shown) as disclosed in embodiments herein. In this embodiment of the disclosure, the template (not shown) is designed having two different solid forms mounted in a framed structure of 3.4 m length and 1.7 m width. The template is positioned over and in contact with a surface (2). In this non-limiting example, the forms had an oval and a wavy shape, respectively, corresponding to the shapes of the cavities on the left and right side of the first layer (1.1) shown in FIG. 2.

[0169] In the same embodiment, the first mixture (M.sub.1) is deposited from a first distributor onto the surface, and over the template. The deposition of the first mixture (M.sub.1) is performed by moving the distributor over and along the length of the template, while discharging the first mixture (M.sub.1) all through the template width. Once the discharging of the first mixture is concluded, the template is removed leaving a first layer (1.1) of the first mixture (M.sub.1) on top of the surface, having the two cavities (3) with shapes corresponding to the forms in the template. Although the first mixture is self-supporting, and the cavities (3) are retained without fully collapsing, about 10% of the volume of the cavity might be filled with the first mixture (not shown in FIG. 2) upon removal of the template.

[0170] The central cavity crossing the first layer (1.1) from lateral edge to lateral edge might be created using a wheel-shaped indenter, as disclosed in embodiments above. At the top left of FIG. 2, the cavity (3) is essentially elliptical. Then, at the right side of the slab-shaped first layer (1.1), it is shown a cavity (3) having a vein shape extending over the whole thickness h.sub.1 of the first layer (1.1) and showing substantially vertical walls (4). Finally, the central cavity is shown having a vein shape extending over the whole width of the slab-shaped first layer (1.1), crossing it laterally, and presenting inclined walls (4).

[0171] In an embodiment, each cavity (3) is defined by a width w.sub.i varying along the length L.sub.i of the cavity (3) or a width w.sub.i varying along the first thickness h.sub.1 of the first layer (1.1) or varying along both the length L.sub.i and the first thickness h.sub.1 of the first layer (1.1).

[0172] In the same embodiment, each cavity (3) presents a first wall portion (4.1) and a second wall portion (4.2) in opposition through the at least one cavity width w.sub.i and extending at least partially along the cavity length L.sub.i, and throughout the first thickness h.sub.1 of the first layer (1.1) of first mixture (M.sub.1).

[0173] In some embodiments, at least one cavity (3) in the first layer (1.1) is created by means of a wheel-shaped indenter, for example, the wheel-shaped indenter (7) further shown in FIG. 7. The at least one cavity (3) might be created by moving the wheel-shaped indenter (7) through the first layer (1.1) when inserted in the first layer (1.1). Thus, in the embodiment of FIG. 2, by following certain trajectories with the indenter (not shown), the central cavity (3) defining at least one cavity wall (4.1, 4.2) is created as a result of the indenter pressing and/or displacing the first mixture (M.sub.1). The depth and width of each cavity can be controlled by controlling the depth to which the wheel-shaped indenter (not shown in FIG. 2) is inserted into the first layer (1.1). Other shapes and designs of the indenter and of the cavity created are contemplated in other embodiments of the disclosure.

[0174] Also in an embodiment, the first layer (1.1) of first mixture (M.sub.1) is deposited onto the surface (2) by means of a first distributing means (not shown).

[0175] FIG. 3 is a view from above of the embodiment also shown in FIG. 2. This embodiment depicts a first layer (1.1) of a first mixture (M.sub.1) after performing a first a) and second b) step of the method for the manufacture of slabs of artificial agglomerated stone. As also shown in FIG. 2, the first layer (1.1) of first mixture (M.sub.1) is deposited onto a surface (2), wherein the first layer (1.1) has a shape corresponding to the shape of the slab to be manufactured.

[0176] In FIG. 3, the 3 cavities (3) show a first wall portion (4.1) and a second wall portion (4.2) which are 2 portions (4.1, 4.2) of the perimeter of each cavity (3) and where the portions (4.1, 4.2) are wall portions opposed through the width of each cavity (3). Also in FIG. 3, the wall portions (4.1, 4.2) are represented as circled and are small segments or sections of the perimeter of each cavity (3). That is, the cavity walls (partially shown in this Figure) can be divided in a multitude of small segments where one of the multitude of small segments can be selected as a first wall portion (4.1). The second wall portion (4.2) is always defined as the wall portion in opposition to the first wall portion (4.1) through the at least one cavity width w.sub.i.

[0177] Furthermore, each wall portions (4.1, 4.2) defines a segment of the upper surface of the cavity walls (partially shown in this Figure) of each cavity (3), the upper surface being the top of the first layer (1.1) of first mixture (M.sub.1). Both of these wall portions, the first wall portion (4.1) and the second wall portion (4.2), are separated by a distance equal to the width w.sub.i crossing one unique point of the cavity length L.sub.i. Each cavity width w.sub.i, defined by two opposite wall portions (4.1, 4.2) is crossing one unique point of the length L.sub.i of each cavity (3) following the shape of the cavity (3). Also, the first wall portion (4.1) always defines the side of the cavity wall or wall portion to be stirred.

[0178] FIG. 4 shows the following step of the manufacture of a slab of artificial agglomerated stone where a second mixture (M.sub.2) has been deposited into each previously created cavity (3) of the first layer (1), to form jointly with the first mixture (M.sub.1) a second layer (1.2). The second layer (1.2) presents a second thickness h.sub.2.

[0179] In some embodiments, the first and/or second walls (4), or first and/or second wall portions (4.1, 4.2) of the cavities (3) created in the first layer (1.1), before the second mixture (M.sub.2) is deposited into them, are sprayed using a nozzle mounted on a robotic device (not shown in the Figures) with a dark black pigment composition comprising styrene and a dye.

[0180] Subsequently, a second distributor (not shown) mounted on a robotic device deposits the second mixture (M.sub.2) into the cavities (3), creating a second layer (1.2) on top of the surface by the combination of the first and second mixtures (M.sub.1 and M.sub.2). The second mixture (M.sub.2) is discharged in controlled amounts as the robotic device is moved over the first layer (1.1). The depositing of the second mixture (M.sub.2) is predominantly made into the cavities (3), filling them to more than 75 weight percent of their volume, and with 1 to 5 weight percent of the second mixture (M.sub.2) being deposited outside the cavities (3) (not shown) in areas proximal to or not farther than 10 cm from the cavity walls (4). In the embodiment shown in FIG. 4, the second layer (1.2) has a thickness h.sub.2 practically identical to the thickness h.sub.1 of the first layer (1.1).

[0181] In some embodiments, the second mixture (M.sub.2) at least partially fills each of the cavities (3), for example, it fills 75% to 100% of the volume of each of the cavities (3).

[0182] In another embodiment, the second mixture (M.sub.2) is deposited in excess and some of the second mixture (M.sub.2) overflows or forms a bulge reaching out of each cavity (3).

[0183] In some embodiments of the disclosure, the first mixture (M.sub.1) and/or the second mixture (M.sub.2) comprises between 80 weight percent to 95 weight percent of inorganic filler and 5 weight percent to 20 weight percent of hardenable binder. Additionally, the inorganic filler of the first mixture (M.sub.1) and/or the second mixture (M.sub.2) comprises 5 weight percent to 50 weight percent of silicate glass, translucent synthetic silicate, or mixtures thereof. Finally, the hardenable binder is an organic resin, hydraulic cement based or a geopolymer based material. Further for example, the organic resin is a translucent organic resin and/or an unsaturated polyester resin.

[0184] In an embodiment, the first mixture (M.sub.1) and the second mixture (M.sub.2) have different composition or different inorganic filler particle size distribution or both.

[0185] In further embodiments of the disclosure, the two mixtures (M.sub.1 and M.sub.2) are previously prepared in separated planetary mixers comprising different amounts of granulates and powders, having different particle sizes, of quartz, synthetic cristobalite, feldspar and recycled silicate glass, and a liquid transparent unsaturated polyester resin. Two different pigment mixtures are added to each of the mixtures (M.sub.1 and M.sub.2) so that they have a different coloration. For example, the amount of granulates and powders make is 85 weight percent to 90 weight percent of the total weight of the mixtures (M.sub.1 and M.sub.2), while the remaining 12 weight percent to 7 weight percent is made up by the resin, with the remaining 0.5 weight percent to 3.0 weight percent being colorants, catalysts, accelerants and other additives. Both mixtures (M.sub.1 and M.sub.2) comprise 15 weight percent to 30 weight percent of silicate glass, in relation to the total weight of each mixture (M.sub.1 and M.sub.2).

[0186] FIG. 5 shows the step after forming the second layer (1.2) by depositing the second mixture (M.sub.2) into the cavities (3) of the first layer (not shown). In that particular step, a first tool (5) in inserted, at least partially, into the second thickness h.sub.2 of the second layer (1.2) and then the first tool (5) is actuated wherein the first tool (5) is configured to stir a first wall portion (4.1) of each cavity (3) while not stirring a second wall portion (4.2) opposed to the first wall portion (4.1) along the cavity width w.sub.i. The stirring of the first wall portion (4.1) of each cavity (3) is responsible for the asymmetrical intermingling effect sought by the method of the disclosure.

[0187] In an embodiment, the first tool (5) is in the form of a blade, rake, fork, trident, stirrer, impeller, paddle, whisk or beater.

[0188] FIG. 6 shows an embodiment of the first tool (5) responsible for stirring one of the two opposing wall portions, in particular the area of the second layer (1.2) where the first opposing wall portion (4.1.) is located (not shown in this FIG. 6, but in FIG. 5).

[0189] In some embodiments, the first tool (5) presents a plurality of separated prongs (5.2). In further embodiments, the first tool (5) presents from 2 to 8 separated prongs (5.2). In the embodiment shown in FIG. 4, the first tool (5) presents three separated prongs (5.2). The separated prongs (5.2) are distributed homogeneously, or not, around the rotation axis X-X′.

[0190] In an embodiment, the first tool (5) presents a plate (5.1), such as round, which is rotatable around the axis X-X′, which might be essentially parallel to the second thickness h.sub.2 of the slab-shaped second layer (1.2) as shown in FIG. 3. For example, the plate in the first tool (5) is shaped as a closed curve, such as a circle, an ellipse, an oval or an ovoid, ranging from 1 cm to 30 cm, or such as from 2 cm to 20 cm.

[0191] Also in an embodiment, the first tool (5) has a larger outer diameter and a length and/or a width of 1 cm to 30 cm, such as 2 cm to 20 cm.

[0192] In some embodiments, the first tool (5) is provided with a projecting head (not shown) for a second pigment composition. The projecting head, when in use, projects or sprays the second pigment composition to the areas of the second layer being stirred by the first tool (5).

[0193] In an embodiment shown in FIG. 6, the first tool (5) is configured comprising a round ‘fork’, formed by three-prongs (5.2) homogeneously distributed around a rotation axis X-X′ and fixed to a round plate (5.1) with an outer diameter of e.g. 10 cm. This tool can be coupled to the end (or hand) of a robotic arm, to be inserted into the second layer (1.2), more preferably in an area of the second layer (1.2), where a first cavity wall portion (4.1) of the cavity (3) is present. When in use in embodiments of the method of the disclosure, the first tool (5) is inserted into the second layer (1.2) so that it contacts the first cavity wall portion (4.1), but it does not contact the opposed cavity wall portion, or second cavity wall portion (4.2), which is opposed to the first cavity wall portion (4.1) through the cavity width w.sub.i.

[0194] When in use in embodiments of the inventive method, the first tool (5), for instance, the first tool (5) shown in FIG. 6, is firstly inserted into the second thickness h.sub.2 of the second layer (1.2) until the separation of the end-parts of the prongs with the surface (2) is approximately 1 cm. Then, the first tool (5) is actuated (in this example, by a computer program) to produce the rotation of the three prongs (5.2) around the rotation axis X-X′, and simultaneously moved following the longitudinal path along the second layer (1.2) of the first cavity wall portion (4.1), e.g. for 5 to 30 centimeters, while avoiding contacting the opposed second cavity wall portion (4.2) along the path. This is schematically shown in FIG. 5. The rotation of the three prongs (5.2) produces the intermingling of the first and second mixtures (M.sub.1 and M.sub.2) in the areas where the first wall portion (4.1) is present. The second opposed cavity wall portion (4.2) is not stirred by the round fork (5). The same process is repeated in the other two filled cavities (3) present in the second layer (1.2) of the present embodiment, along different portion lengths along the longitudinal paths of their respective cavity wall sections (4).

[0195] In an embodiment, the second opposing wall portion (4.2) is not stirred by the first tool (5), or by any other tool, during the manufacture of the slabs of artificial agglomerated stone.

[0196] Once the stirring with the first tool (5) is completed, in subsequent steps not shown in the Figures, the second layer (1.2) is covered on its exposed surface with a protective sheet, e.g., of Kraft paper, before it is transferred to a vacuum vibrocompaction press. For example, after compaction, the second layer (1.2) is hardened in a kiln for about 40-60 minutes at 70-110° C.

[0197] The compacted and hardened slab of artificial agglomerated stone obtained according to these embodiments, are trimmed and calibrated to the final dimensions, e.g., of 3.3 x 1.6 cm, and one of the two major surfaces is polished to enhance the appreciation of the chromatic effects created.

[0198] Before use in the final application, the slabs of artificial agglomerated stone are cut-to-size, whereby the chromatic effects created are visible through the slab thickness in the edges of the cut pieces.

[0199] FIG. 7 shows an embodiment of the indenter (7) for creating a cavity in a first layer (1.1) of first mixture, e.g., as the central cavity shown in FIG. 2. For example, as shown in FIG. 7, the indenter (7) is a wheel-shaped indenter shaped as two frustums (7.1) of right cones joined by their bases, such shape provides to the indenter (7) a maximal wheel outer diameter D at the location of the junction of the frustums (7.1). In this configuration, the rotation axes Y-Y′ coincides with the frustum (7.1) axes.

[0200] In some embodiments, the maximal width size T of the wheel-shaped indenter (7) is suitably selected corresponding to the maximal width of the at least one cavity to be achieved in the first layer.

[0201] In some embodiments, the width T of the wheel-shaped indenter (7) might range from 20 mm to 120 mm, or 30 mm to 110 mm. Also, the maximal outer diameter D of the wheel-shaped indenter (7) might range from 100 mm to 300 mm, or 150 mm to 250 mm.