BR112018000363B1 - PRODUCTION PLANT FOR THE FORMATION OF DESIGNED COMPOSITE STONE SLABS - Google Patents

Abstract

PRODUCTION PLANT FOR THE FORMATION OF DESIGNED COMPOSITE STONE SLABS. An engineered stone production plant includes a vacuum vibrating press ("VVP") suspended above ground so that a conveyor belt and/or empty trays or molds return from a curing oven to a mixture can pass under the VVP. Rigid, self-supporting trays or molds can transport slabs through the plant in rolls, which allows for independent horizontal movement of the slabs during spreading and staining/rib forming of the slab mix. Modalities include air levitation for transporting slabs into and out of the VVP. The curing oven can be heated with air. The press plate may be sealed to the tray or mold by walls extending downwardly from the press plate onto a flexible cover sheet, by a gasket that surrounds the press plate, or by an angle strip that surrounds the press plate. the slab mix. In embodiments, the slab size can be changed by changing elastomeric mold walls, or by changing molds and press plates.

Description

FIELD OF THE INVENTION

[001] The invention relates to engineered stone slabs, also known as Breton stone slabs or quartz slabs, and more particularly, to production plants for the manufacture of engineered stone slabs.

BACKGROUND OF THE INVENTION

[002] Engineered stone slabs are a specialized, non-porous, high-performance type of composite stone slab that emulates both the physical and visual properties of natural stone slabs. The term "composite stone" is very broad and can be applied to any material that is formed by the adhesion of stone particles together. The most common forms of composite stone, such as asphalt, regular cement, or polymer cement, are not intended to mimic natural stone and do not even remotely approximate the physical properties or appearance of natural stone slabs.

[003] Engineered stone slabs, on the other hand, are a very specialized sub-category of composite stone slab that, until recently, was manufactured exclusively through a highly specialized and expensive type of engineered stone production plant invented by M. Toncelli of Breton S.p.A, and marketed by Breton since the 1980s. More recently, copies of Breton's production plant design have been manufactured and sold by other sources, but Breton's production plant design has remained the only plant design known to be capable of producing engineered stone up to the present invention. Consequently, engineered stone slabs are also sometimes referred to as "Breton stone slabs". Most commonly, a high percentage of the stone included in an engineered stone slab is quartz. Therefore, engineered stone slabs are also sometimes called "quartz slabs". Other terms for this highly specialized type of stone slab are "ES-BS" (Engineered Stone - Breton Stone) slabs or "ES-BS-QS" slabs (Engineered Stone - Breton Stone - Quartz Stone). Likewise, the production plant that has been used so far to manufacture all engineered stone slabs is often revered as the Breton production plant or Breton stone plant, and the vacuum vibrating press ("VVP") which is included in the Breton stone plant is often referred to as a Breton press.

[004] Referring to Figure 1A, the 126 slab mix used to manufacture ES-BS slabs typically includes about 55-65% 128 stone granules, 22-30% -325 mesh stone dust, and between 6% and 10% resin binder, which is a liquid composed of resin, pigment and additives. In specialized cases, especially when cristobolite powder is replaced by quartz powder, the percentage of resin can reach 12% due to the high surface roughness of cristobolite particles. Otherwise, resin is typically 10% or less. This resin binder, combined with the -325 mesh powder, forms a binder paste 130 which binds the stone granules 128 to form the ES-BS slab. A slab mix containing more than 15% liquid is by definition not an ES-BS slab mix.

[005] Due to the relatively low percentage of resin binder in shot stone (typically 6% to 10%) compared to, for example, the relatively high amount of water or polymer binder in concrete, there is not enough binder in a stone slab mix designed to fill all voids between 128 stone granules as they are naturally laid out after mixing. As a result, an engineered stone slab mix initially contains a lot of entrained air 134. And because there is not enough resin to fill the voids, gentle agitation and vibration will only cause the mix to settle, without eliminating the voids between the stone granules and not can transform an engineered stone mixture into a void-free article.

[006] Consequently, it is necessary, when fabricating a stone slab of ES-BS 132, to force the stone granules 128 in the slab mix into a "closed package" configuration, as illustrated in Figure 1B, where the granules of stone 128 are migrated under intense pressure and strong vibration from their natural, essentially random distribution, as shown in Figure 1A, in a space-filling, closed-pack arrangement that minimizes the total volume of voids between the stone granules 128, as illustrated in Figure 1B. If this closed-pack stone granule configuration is not achieved, there will be insufficient binder paste 130 to completely fill all the voids between the stone granules 128 and therefore it will be impossible to produce a non-porous slab with similar properties and appearance to slabs. of natural stone. At best, the result will be a porous slab with very few qualities and appearance. The closed packing arrangement of the stone granules and the achievement thus of a non-porous result when the starting mixture contains too little resin to fill all the voids without a close packing is a defining characteristic of an engineered stone slab. .

Definitions of terms

[007] Note that the following terms are used with the definitions indicated throughout this work.

[008] Composite stone: Composite stone refers to all materials that are made using some type of binder to glue any type of stone materials such as sand, gravel, marble, broken clay pieces, glass, mirror, quartz or granite. Virtually any natural mineral or other inorganic material that is hard relative to the intended end use of the composite stone article can be used. There are many types of composite stone, including, for example, concrete, terrazzo, concrete blocks, concrete or cement pavers and slabs, large concrete slabs, as they are used for the manufacture of buildings or bridges, concrete road pavements, slabs and polymeric concrete articles, cement or resin slabs based on decorative marble, and finally, engineered stone slabs.

[009] Engineered Stone Slabs, also referred to as Breton Stone Slabs, Quartz Slabs, Slabs (ES-BS) or ES-BS-QS Slabs. These terms are used synonymously here to refer to a special class of composite stone slabs that contain more than 85% stone content and less than 15% resin binder. The slabs are non-porous, with no voids inside or on the slab surface, and closely mimic the appearance and physical properties of natural stone slabs. Until the present invention, all these slabs were produced using a specialized and expensive vacuum vibrating press invented about 25 years ago by Breton S.p.A, and obtained either from Breton, or more recently from other sources producing copies of the design. from Breton. The invention of engineered stone and the invention of the Breton press coincided, since the Breton press was specifically designed to produce engineered stone, and until the engineered stone of the present invention could only be produced using a press of the Breton design.

[0010] Stone Granules (SG), also referred to here as granules or aggregates: This term generically refers to particles of stone (typically quartz or silica-based stone), or other hard materials (such as glass, granite , marble and the like), having sizes in the range of about 0.2 mm to 2-3 centimeters.

[0011] Quartz Powder (QP), also referred to herein as Silica Powder and Filler: These terms refer to powdered material that varies in particle size from about 1 micron to about 300 microns in diameter. In industry, QP is typically finely crushed and/or ground quartz or silica sand. It is readily available worldwide in a generally standard mesh size of less than 325 ("-325"), and can be made from marble (calcium carbonates), silica, quartz, glass, granite, or any other material that can be powder and used to make quartz slabs. A special form of quartz known as cristobolite (made by heating quartz to over 1000 degrees C) is also used because of its unique whiteness. Due to the high surface roughness of cristobolite particles, and the corresponding high oil absorption, an additional 1% to 2% resin is normally required to wet the surfaces of cristobolite granules, in addition to the 6% to 10% resin required for fill in the gaps between the granules. Consequently, for cristobolite-based ES-BS slabs, between 8% and 12% total resin is typically required.

[0012] Resin: This term is used here to refer to any resin and/or adhesive system capable of adhering stone granules and quartz powder together to form an engineered stone slab. Examples include epoxy, urethane, acrylic, vinyl ester, silicone resins and even cement adhesives based on the various forms of hydraulic type cements. When the resin is a polyester material, it may include various additives that affect the cure rate and especially the adhesion of the resin to silica and/or quartz based minerals and granites. In the quartz slab industry, the resin is, for economic reasons, typically a modified polyester thermosetting resin.

[0013] Vacuum Vibrating Pressure (VVP): This term is used here to refer to an apparatus that can simultaneously apply sufficient pressure, vibration, and vacuum to a stone slab mixture designed to force the stone granules into the mixture into a closed packing relationship that allows for the limited amount of resin slurry in the mix to fill any remaining voids between the stone granules. It is the achievement of this closed packaging configuration that allows the fabrication of an engineered stone slab. Until the present invention, the only type VVP that was able to apply sufficient vibration and pressure to create a closed package of an ES-BS slab mix was the Breton style VVP and its copies.

[0014] It is important to note that the terms Vacuum Vibrating Pressure, Vacuum Vibrating Pressure and VVP, as used herein, do not apply to all types of presses that can simultaneously apply pressure, vibration and vacuum to a slab mix. . For example, polymer concrete slabs are sometimes manufactured by a press that applies small amounts of pressure, vibration and vacuum to a PC slab mix. However, such an apparatus did not meet the definition of a VVP as used herein, because the polymeric concrete press would not be able to apply sufficient pressure and vibration force to a stone slab mix designed to achieve a closed package close to the stone granules.

[0015] It should be noted that such NC-PC forming devices that include both vacuum vibration and pressure are very rare, because generally the vacuum and pressure functions are unnecessary for settling and flattening NC-PC mixtures. When vacuum vibration and pressure are employed by an NC-PC device, the amounts of vibration and pressure forces these devices apply are a minuscule fraction of the forces required for closed packaging of ES-BS slab mixes.

[0016] Closed Packing (CP): This term refers to a tightly packed arrangement of stone granules in an ES-BS slab mix, which does not occur naturally but can only be achieved by applying strong pressures and vibrations. in the mixture (as well as vacuum to remove entrained air in the mixture). The applied pressure provides the "motivation" for the beads to become tightly packed, and very intense vibration causes the stone beads to move and "shake" so that they can reorient and move towards each other until a relationship of closed packaging be achieved. Achieving a closed packing arrangement of the stone granules in an ES-BS slab mix is necessary for the production of ES-BS slabs.

[0017] Closed Pack Energy (CPE): This term refers to a combination of high pressure and intense vibratory energy that is applied to the stone granules within an ES-BS slab mix and is sufficient to force the granules stone in an ES-BS mixture to reorient and migrate to a closed-pack arrangement. Until the present invention, the only press design that was capable of delivering CPE to an engineered stone slab mix was the Breton design. Note that CPE is a combination of pressure and vibrational energy, and that different combinations of pressure and vibrational energy can provide CPE. Also note that the vibratory energy included in the CPE is the vibratory energy present in the slab mix, which will depend on the efficiency with which external “input” vibratory energy applied to the surface of the slab mix is transmitted into the interior of the slab mix. .

[0018] Sedimentation Energy (SE): This term refers to low to moderate vibrations that are sufficient for a normal concrete mix or a polymer concrete mix to settle and most of the air entrained in the mix to rise. to the surface, but it is not sufficient to apply CPE to an engineered stone mix. Note that the amount of SE that is required to sediment a PC-NC slab mix depends on the total weight of the slab mix being processed. Per square foot, the Settling Energy required for NC-PC slabs is only a small percentage of the CPE needed to form ES slabs.

[0019] SLAB: When this term is used here in all capital letters, it refers to an engineered stone slab with an area of approximately 44 square feet and a thickness between 1 cm and 3 cm. This slab size is industry standard. Older versions of the Breton VVP made slightly smaller slabs, and later models form slightly larger slabs. But, the term SLAB is used here to refer to the standard 44 square feet, 1-3 cm thick engineered stone slab. A 1 cm thick SLAB weighs approximately 230 lbs, a 2 cm thick SLAB weighs approximately 460 lbs, and a 3 cm thick SLAB weighs approximately 700 lbs.

[0020] Most of the figures and discussions presented here are applicable to engineered stone slabs of any size. However, when specific dimensions are given for components of the disclosed production plant, these dimensions generally apply to a plant that is configured to produce "jumbo" slabs, with dimensions @ 132" x 62", or "standard" slabs, with dimensions @ 122" x 54". Note that throughout the description and drawings presented herein, the symbol "@" is used to convey the meaning "approximately" or "substantially", depending on the context.

[0021] Pressure: This term is used here to refer to the process of simultaneously applying vacuum, pressure and vibration to a stone slab mix designed in a combination providing CPE to the ES-BS slab mix, and thus forces the stone granules in the mixture in a closed packing arrangement. Until the recent invention of the VVP disclosed in US Application No. 14/222,695 and related orders, the only VVP style that could accomplish this was the Breton style press and its copies.

[0022] NC-PC Composite Stone: This term is used here to refer generically to composite stone products, in which the stone granules are not packaged closed. Examples are "normal concrete" and "polymer concrete". In an NC-PC slab mix, enough liquid is supplied to fill all the voids between the stone granules as they are naturally laid out when the slab mix is first prepared. As a result, only very modest vibrations and possibly a small amount of pressure are needed to level the mixture and to encourage ingrained air bubbles to rise to the surface and be eliminated.

[0023] NC-PC Vibration Table: This term is used here to refer to an apparatus designed to produce an NC-PC product and which is not capable of applying CPE to a stone slab mix, even though it may be able to apply more moderate levels of vibration to an NC or PC slab mix, possibly with vacuum, and in rare cases also with a small amount of pressure.

The Breton Production Plant Project

[0024] The Breton stone production plant design for the manufacture of engineered stone slabs has been in use since the mid-1980s, and has remained unchanged in its main design features, with the exception of minor modifications introduced periodically, such as the introduction of a complicated rubber molding system as an alternative to the previously used sheet of paper.

[0025] Figure 1C illustrates the basic steps used to manufacture ES-BS slabs according to the Breton method. First, the slab mix is prepared 100. Typically, this includes preparing a mix containing about 65% stone granules 102 (small grains from 0.2 mm to 1 mm, as well as aggregates from 1 mm to 1 mm. 25 mm), such as crushed quartz, granite, mirror and/or glass in bead sizes from 0.2 mm to 6 mm or even 15 mm. About 25% "quartz powder" 104 is also included, where the term "quartz powder" generically refers to one or more powdered minerals such as silica and/or quartz (or cristobolite quartz powder), typically at a mesh of approximately minus 325 (minus 45 microns). Finally, about 6 to 10% resin 106 is included, typically with additives such as catalyst 108, pigment blends 110 and dispersing media. It is also possible to make ES-BS slabs with powders and granules based on calcium carbonate and marble, although the finished product has lower scratch/abrasion resistance and lower chemical resistance.

[0026] After the raw materials are weighed and measured, they are transported to a mixer 112 and mixed 114. Typically, the mixer is loaded with the stone granules, resin, pigments, additives, etc., and the combination is mixed until the particles and granules are completely wet. For color design purposes, two, three or more mixers can be used, each with a different color of raw materials and pigments. This is illustrated in Figure 1D.

[0027] Quartz powder is then added while mixing continues. When combined with the resin, the quartz powder forms a binder paste that serves as a binder between the stone granules. The blended materials are then formed into a single slab 116, either in a rubber mold, a metal mold, or a sheet of paper or other suitable conveyor that can be used to transport the formed slab to the vacuum vibrating press. (VVP). Note that the order of addition of the various materials can sometimes be changed for efficiency or other reasons.

[0028] As illustrated in Figure 1A, when the shot stone mixture 126 is mixed and placed in the mold, there is not enough resin and powder to fill all the voids between the stone granules 128 and therefore the mixture contains a significant amount 134, and therefore functions as a 2-phase system, where Phase 1 is the grains and aggregate pieces 128, and Phase 2 is the binder slurry 130. The mixture is difficult to move, and seems almost dry because of the small percentage of binder paste and the large percentage of stone granules. Entrained air does not and cannot "rise" out of the 126 mixture if only vibration is applied, because the powder and resin binder is so dry and rigid that it traps air, and also keeps the granules in their naturally occurring arrangement. , "open" (ie not closed packaging).

[0029] A typical Breton stone production plant is illustrated in Figure 2. The slab mix is prepared in a 200 m high 3.5m mixing station including one or more large batch mixers, one or more color mixers , and a spreading conveyor belt 202 for conveying the slab mix 224 to a spreader 204, which then distributes the slab mix 224 over a conveyor conveyor belt 206 which transports the uncompressed slab 126 to the vacuum vibrating press 208 and then transports the compressed slab 132 to the kiln system 210. Note that changing colors in a Breton plant requires cleaning work by 6 people for 5-6 hours. Furthermore, the Breton-style mixing station can cost between $2.5 million and $3.5 million.

[0030] A void-free compressed plate 132 can only be formed from the uncompressed mixture 126 if the stone granules 128 are compacted in a closed package configuration (see Figure 1B), so that the two phases are merged. Therefore, when the mixed material 224 is spread and formed into a slab 126 on conveyor belt 206, it is generally 15-50% thicker than the finished slab 132 will be after pressing, because the granules 128 have not yet been forced into bonding relationship. closed packaging. For example, for a 2 cm thick SLAB, the spread and leveled material can be 2.3 to 3 cm thick before pressing. If this mixture were processed in an NC-PC press, which would not be able to apply CPE to the mixture, the mixture after pressing would still be 10-30% thicker than if CPE had been applied, and it would be porous, because the stone granules would be in a normal, uncompacted ratio, and so the mixture would still contain a significant amount of entrained air. Note that there is no vibrating table or NC-PC vibrating press that is capable of applying even a small fraction of the pressure and vibration required to apply CPE to an engineered stone slab mix.

[0031] Once the formed slab mix 126 has been transferred to the press 208, it is simultaneously evacuated, vibrated and pressed 118 in the Breton type VVP 208 in order to compact the mixed material 126 by forcing the granules into a closed packaging arrangement 132, thus minimizing the void volume between the granules 128 so that the small percentage of the binder slurry 130 is sufficient to fill all the remaining space between the granules 128 and there will be no voids 134 in the finished non-porous slab 132.

[0032] Once the slab 132 has been pressed, it is transported by the conveyor belt 208 to an oven 210 or to some other location for curing 120. Depending on the adhesive (resin) used to bind the particles together on the slab, the The curing and hardening process can take place at room temperature or at an elevated temperature, and can take from a few minutes to many hours. After curing and hardening, slab 132 is returned to room temperature (if heat has been applied).

[0033] The typical Breton curing oven 210 includes about 18 pairs of oil heated plates 212 which are applied to the tops and bottoms of each of the 18 pressed slabs 132 which are arranged horizontally on top of each other in the oven 210 This approach consumes a significant amount of energy, and is not easily adapted for use with slabs of varying sizes.

[0034] In a typical Breton plant design, furnace 210 extends 1 floor below ground and 2 floors above ground. In general, it consists of 16-20 pairs of aluminum plates 212 which sandwich the slabs 132 after pressing. Each of the pairs of heating plates 212 must be configured to open a space between them, allow the slab 132 to be inserted therein, and then close together to sandwich the slab 132 between them during heating. The heating of the plates 212 is accomplished by pumping hot oil through them. This heating system is very complex, and includes many hoses (not shown), which must extend up and down the lift system as plate pairs 212 are moved up and down for loading, curing, and emptying. . The Breton 210 oven is also very expensive. A typical Breton kiln to cure @ 30-40 slabs per hour, weighs around 50 tonnes, costs approximately US$3 million and requires frequent cleaning of the upper and lower heating plates for each slab due to contamination of the heating plates by the resin that escapes from the slabs.

[0035] A well-known and costly defect in the Breton oil-heated plate furnace system is that the temperature of the heated slabs 132 is not consistent, neither in the area of each individual slab nor from slab to slab at different levels in the heating system. oven 210. The temperature variation can be +/- 10o C or more. Since the target cure temperature for polyester-based slabs (note that polyester is the most commonly used thermosetting resin) is around 80-100o C, a +/- 10 degree range is very problematic as: 1) to get the entire area of each slab to the same temperature, the slabs must remain in the oven for an extra 10-30 minutes; 2) when the slabs cure at different temperatures in different areas of the slab (or worse, if some areas do not reach full cure), then the complete sheet will have different degrees of cure and therefore varying degrees of slab shrinkage, leading to residual internal stress that can cause future bending or cracking.

[0036] After curing, the slab 132 is then graded and polished 122 to a desired thickness and finish, using technology similar to that used to grind, grade and then polish conventional natural granite stone slabs. The end result 124 is a finished ES-BS slab that is non-porous and closely matches the appearance and physical properties of natural stone slabs. Note that the presence of a single void on the surface of a slab will yield the "second quality" slab, and more than two of these voids will become the unsaleable slab.

Disadvantages of the Breton project

[0037] Breton Vacuum Vibrating Press (VVP) is effective in producing ES-BS slabs as it offers a combination of high pressure force and very high vibrating energy under vacuum which is sufficient to apply CPE in a mixture of engineered stone slab, thus forcing the stone granules into a closed packing arrangement. However, there are several disadvantages associated with the Breton style of VVP and production plant.

[0038] The disadvantages of Breton's VVP design, which are overcome by the new design recently introduced by the present inventor, are discussed in detail in US Patent Application Nos. 14/729,823 and 14/222,695. One of the disadvantages of the Breton VVP that leads directly to disadvantages elsewhere in the Breton plant design is the fact that a Breton 208 press includes a 20-ton 222 steel base, which must be anchored to a vibration dampened block. of 300 tons of reinforced concrete 214 which is positioned below the concrete floor 216. The vibration dampened block 214 is approximately 20' long by 15' wide by 20' deep. Its purpose is to force some of the applied vibratory energy into the slab material 126 so that the closed package can be achieved. However, a Breton 208 style press has very low energy efficiency. Even with the 300+ ton base 222 and block 214 as an inertial mass that resists the rapid vibrating motion that is delivered to the press plate 218 by the vibrating device 220, only a small percentage of the vibratory energy enters the slab material. 126 to perform the necessary closed packaging. This is in part because massive base 214 is only inertial, and is actually not a good "reflector" of vibrating energy back to slab 126.

[0039] Due to the requirement for this massive inertial base 222, 214, the conveyor belt 206 at the Breton plant is forced to transit VVP 208 twice so as to return in a loop. This double layer of conveyor belt 206 that passes under the slab 126 absorbs even more energy from the press and makes the press even less efficient.

Comparison between PC-NC slabs and Breton stone slabs

[0040] In order to fully understand the present invention and how it is distinguished from the prior art, it is important to understand the distinctions between engineered stone slabs and other types of composite stone products and the devices that are designed to make them, referred to herein. generically as PC-NC products and vibration tables. The vast majority of composite stone materials, mainly concrete and polymeric concrete, are produced for structural and/or industrial purposes, while engineered stone is mainly produced for decorative purposes. There have been some attempts in the last 30 years to produce a decorative non-Breton stone composite stone product, but they have mostly been unsuccessful. These include PBI, which failed in the decorative market; Granitech, which also failed in the decorative market; GRANIT 90, which is still produced but in very small quantities, and RESPECTASTONE, which is currently not on the market due to high resin content and unsatisfactory appearance and physical performance compared to Breton stone.

[0041] Since the purpose, design and effect of ES-BS and PC-NC devices and products produced are so different, experience in one area does not easily translate into expertise in the other area. Experts in the field of polymer concrete and normal concrete (PC-NC) and experts in the field of shot stone do not normally discuss the distinction between these materials and their very different energy compaction principles, simply because the products produced are in entirely different categories. in terms of use and manufacturing principles. However, there are very important distinctions that must be understood to understand the present invention.

[0042] Normal concrete and cement mixtures have a high liquid content and are generally liquid, fluid and easy to move. Air bubbles embedded in the mixture are often not a problem, as they tend to arise from the mixture due to the high liquid content. Relatively low energy vibrations, applied to the outside of the container or placing the vibrator head in the mix, are sufficient to remove entrained air and settle the mix into the desired shape.

[0043] Polymer Concrete: These mixes have a lower liquid content than normal concrete because polymer is expensive, but the liquid content is still much higher than for an engineered stone mix and is suitable for wetting all grains and pieces of aggregates in the PC mix. A PC mix normally flows easily, and typically can be leveled and formed by applying very modest vibrations, although vacuum degassing can be used to remove entrained air and, in rare cases, gentle pressure can be applied, typically when the PC slab must be pressed into a shape to create a non-flat shape.

[0044] Referring to Figure 3, in a mix of normal concrete or polymer concrete 324, after mixing, stone granules 128 and smaller grains 326 are completely surrounded by a surplus of liquid 328, which is typically water, slurry Portland cement, or polymer. The mixture 324 is a single-phase system in that it is a liquid or semi-liquid "soup" that contains more or less grains 326 and pieces of aggregate 128 moving freely.

[0045] Once there is enough liquid plus fine grains or powder to fill the entire space between the grains 326 and the aggregate pieces 128, an applied vacuum, or vacuum with moderate vibration, will cause any entrained air to rise to the surface. and is removed and typically causes the mixture to flow into a mold, although it is sometimes pressed gently as well, especially when forming non-flat items. This combination of vibration and moderate pressure is referred to herein as "settling energy" or "SE".

[0046] A typical SE vibratory energy would be in the range of 1-5 HP per PC SLAB. This vibrating energy can be delivered by any number of NC-PC vibrating machines manufactured by hundreds of companies. Applying additional strong pressure and vibration to a normal concrete or polymer concrete mix, for example at a level equivalent to CPE, does not further compact the mix because the mix does not include any fillable voids or any other mechanism that allows additional volume reduction. As larger aggregate pieces 128 are moved closer together by SE, typically to the bottom of the mold because their density is greater than polymer-powder or water/cement binder, this process is similar to vibration-assisted settling, and does not result in any special closed packaging of settling parts, or any reduction in volume.

[0047] In contrast, in the fabrication of an ES-BS SLAB, the Breton stone type of VVP applies CPE including an input vibratory energy of more than 100 HP per SLAB.

[0048] There is also a very big difference in the pressure that is applied by a PC-NC press compared to an ES-BS press. Typically, for a PC-NC press, the pressure is solely for flattening the PC-NC slab mix, or for pressing a shape down into the material to create a 3-d shape, such as a trough or basin. As discussed above, since a PC-NC slab mix contains enough liquid and powder to fill all the voids between the grains and aggregates, the mix is not compressible in volume. Therefore, only very modest pressure needs to be applied by the plate or mold. Typically, a PC-NC press only needs to apply one or two psi to the slab mix to achieve the desired result.

[0049] In contrast, forcing the stone granules of an engineered stone mix into a closed packing relationship requires an ES-BS Breton style press to apply very high pressure to the slab mix at the same time as the intense ones. vibrations (and, of course, applied vacuum). Typically, a Breton ES-BS press should apply between 20 and 50 psi.

[0050] There is also a significantly different relationship between slab size and vibratory energy required for PC-NC slabs compared to ES-BS slabs. In the case of PC-NC materials, if the article to be vibrated is lighter, then proportionately less vibrating energy is required. However, this is not true for ES-BS slabs. The same very intense vibratory energy that is needed for a 700 lb 3 cm thick SLAB is also needed for a 250 lb 1 cm thick SLAB. Because? Because, in the case of ES-BS materials, only a very small percentage of the vibratory energy (and pressure) is used as SE energy to flatten or shape the mixture, while most of the vibratory energy is applied as CPE energy to force the closed packaging of grains and pieces of aggregates, regardless of the weight of the slab.

[0051] What is needed, therefore, is a production plant for the manufacture of engineered stone slabs that is much lower in manufacturing and operating costs, requires less maintenance, and is more flexible in terms of changing aesthetic color and size. slab than conventional Breton production plants.

SUMMARY OF THE INVENTION

[0052] A production plant for making engineered stone slabs and other engineered stone products costs less to manufacture and install, provides shorter press cycle times, and requires less energy consumption and maintenance than an engineered stone production plant. engineered stone from Breton. The disclosed production plant includes a vacuum vibrating press ("VVP") that applies as much or more CPE energy to an ES-BS blend formed as a conventional Breton press, while weighing less and requiring less resin in the recipe. slab. The VVP included in the preferred embodiments of the present invention (which is discussed in detail in US Patent Applications 14/729,823 and 14/222,695) does not require the massive base of a Breton press, thus allowing it to be at least partially suspended above the floor so as to provide a passage below the VVP through which a conveyor belt and/or empty return trays or molds can pass. In rigid embodiments, trays or self-supporting molds are used to transport the slabs through the plant. The ability to transport empty trays or molds below the VVP and back to the mixing area for reuse is one of the main reasons why it is practical and economical to use rigid trays or molds in embodiments of the present invention, made for example from anodized aluminum. , which could otherwise be very heavy and cumbersome to handle and transport.

[0053] Various embodiments use rollers to transport the rigid, self-supporting trays or molds to and from the press and curing oven. In some of these embodiments, the trays or molds can be moved independently of each other in at least one horizontal direction. In embodiments, this ability to independently move trays or molds simplifies the mechanism that deposits and spreads the slab mix, and provides opportunities to include new staining and rib forming apparatus to enhance the appearance of the slabs.

[0054] Certain arrangements include an air levitation system for transporting slabs into and out of the VVP. The modalities allow relatively easy and inexpensive exchange of aesthetic color applications and/or the size of the slab being produced. Various modalities also include a new scattering, staining and patterning apparatus. In addition, several embodiments include a new heated air curing oven.

[0055] To better understand how these improvements are related, it is useful to consider how the Breton press design constrains the design of the entire Breton production plant. Due to the massive base of the Breton VVP, the only available path between the spreader and the oven is through the press itself. As a consequence, there is no practical way to automatically return trays or slab support molds to the mixer. Instead, the slabs are laid on sheets of paper that are disposable and do not need to be returned and reused, or on lightweight rubber molds that are easy to handle and manually return to the spreader after use.

[0056] The sheets of paper and rubber molds used in a Breton production plant do not support the slabs, that is, they are not self-supporting. For this reason, they must be transported on a conveyor belt that will maintain the flat shape of the slab as it is spread, transported to the VVP, pressed and then transported to the kiln. Using a conveyor belt restricts the slabs to only move in one direction and prevents the slabs from moving independently of each other. As a result, the spreader must move relative to the conveyor belt when spreading material onto a slab. This significantly increases the cost and complexity of the spreader and limits its flexibility. In addition, due to the massive base of the Breton VVP, the Breton production plant conveyor belt must go through the press twice as shown in Figure 2, which wastes vibratory energy and significantly increases the design complexity and design requirements. maintenance.

[0057] In view of the foregoing disadvantages of prior art production the object of the present invention is to create a production plant to form engineered composite stone slabs providing a return path for the slab transport mechanism and/or the supporting structures of slab under the vacuum vibrating press.

[0058] The solution of the above objective is provided by a production plant to form engineered composite stone slabs comprising the features mentioned in claim 1.

[0059] In particular, because the VVP used in the embodiments of the present invention does not require a massive base, a return path can be provided from the furnace to the spreader under the VVP. As a result, the slabs can be deposited on trays or rigid molds that support the slabs, and the empty trays or molds can be returned on a belt or rollers (or any other conveying mechanism known in the art) below the VVP.

[0060] The limitation of the Breton design to flexible rubber or paper slab supports also means that the Breton curing oven system must provide rigid shelves that support the slabs during curing in the oven, making it impossible for heated air flow easily and evenly around the slabs. Instead, in the Breton kiln design, it is forced to resort to sandwiching the slabs between rigid, oil-heated plates.

[0061] In contrast, preferred embodiments of the present invention include curing ovens that provide only limited support to rigid trays or molds, such as support rails along the sides, and thus can allow heated air to flow freely through the interior, eliminating the need for oil heating of the slabs during curing.

[0062] In addition, the use of trays or rigid slab support molds allows the use of transport mechanisms, such as rollers and/or air support systems, which allow independent movement of the slabs in any desired horizontal direction, from so the spreader design can be simplified.

[0063] Accordingly, preferred embodiments of the present invention include one or more of the following: • A slab conveyor system that includes a component that passes below the VVP • A rigid tray or mold, which may be anodized aluminum; • A continuous mixer; • A spreader and/or coloring system that takes advantage of the independent horizontal movement of the slabs during spreading and/or coloring; • An interchangeable press plate to change slab size • Interchangeable rubber mold walls to change slab size and thickness

[0064] A first general aspect of the present invention, referred to herein as embodiment 1A, is a production plant for forming engineered composite stone slabs. The production plant includes a vacuum vibrating press capable of applying vacuum, pressure and vibrating energy to a formed slab mixture deposited on or within a slab support structure, said slab mixture containing stone granules, stone powder and a resin binder, said resin binder is not more than 15% of the slab mix by weight, said vacuum, pressure and vibratory energy in a combination of amplitudes that is sufficient to compress said slab mix formed into a closed configuration wherein all the voids between the stone granules and the stone powder are filled by said resin binder, said vacuum vibrating press being suspended above a supporting floor so that a passageway is provided between said vibrating press vacuum and said supporting floor; and a slab transport system configured to transport said formed slab mixture into and out of said vacuum vibrating press, a portion of said slab transport system being directed through said passage formed between said vibrating press to vacuum and said support floor.

[0065] Modalities of this first general aspect including the following additional resources:

[0066] 1A1. The production plant of embodiment 1A, wherein the slab conveyor system includes a conveyor belt extending through said vacuum vibrating press and returning through said passageway between said vacuum vibrating press and said supporting floor.

[0067] 1A2. A production plant of modality 1A or 1A1, where the slab conveyor system is configured to allow the slab support structure to move in at least two orthogonal directions while the slab mix is deposited on or into the slab structure slab support.

[0068] 1A3. The production plant of any one of embodiments 1A-1A2, wherein the slab transport system includes rollers on which the tray or rigid mold can be rolled, said rollers including rollers allowing said slab support structure after removal of said stone slab projected therefrom, being rolled down said vacuum vibrating press in preparation for deposition of the slab mix onto or within the slab support structure.

[0069] 1A4. The production plant of any of embodiments 1A - 1A3, wherein the slab conveyor system is configured to allow a plurality of slab support structures to move independently of one another in at least one horizontal direction.

[0070] 1A5. The production plant of any of embodiments 1A - 1A4, further comprising a continuous mixer configured to prepare said slab mix by mixing said stone granules, stone powder and resin binder.

[0071] 1A6. The production plant of modality 1A5, in which said continuous mixer can produce up to 100 kg per minute of the slab mix.

[0072] 1A7. The production plant of modality 1A5 or 1A6, in which said continuous mixer can produce up to 300 kg per minute of slab mix.

[0073] 1A8. The production plant of any of embodiments 1A - 1A7, further comprising an air dampening mechanism configured to support the formed slab mix as it is transported in and out of the vacuum vibrating press.

[0074] 1A9. The production plant of any of embodiments 1A - 1A8, wherein the slab transport mechanism includes at least one slab lift configured to adjust a height of the slab transport system above the supporting floor.

[0075] 1A10. The production plant of any one of embodiments 1A - 1A9, wherein the slab support structure is a sheet of paper or an elastomeric mold.

[0076] 1A11. The production plant of any of the embodiments 1A - 1A10, wherein the slab support structure is a mold having a flat center delimited by vertical walls, and said production plant further comprises a rigid cover plate configured for placement on top of the slab mix formed within said vertical walls during pressing of the formed slab mix.

[0077] 1A12. The production plant of any one of embodiments 1A - 1A11, wherein the slab support structure is a rigid tray or rigid mold.

[0078] 1A13. The production plant of any of embodiments 1A - 1A12, wherein the vacuum vibrating press comprises a vibrating table within a vacuum chamber, said vibrating table being configured to support the slab mix formed from below; a press mechanism within the vacuum chamber, said press mechanism being configured to apply pressure to the slab mixture formed from above; at least one lower vibration device cooperative with the vibration table; and at least one upper vibration device cooperative with said press mechanism.

[0079] 1A14. The production plant of embodiment 1A13, further comprising a flexible cover sheet configured to overlay the formed slab mix and form a seal between the slab support structure and the press mechanism during pressing of the formed slab mix.

[0080] 1A15. The production plant of embodiment 1A13 or 1A14, wherein the slab support structure is a flat structure, and the press mechanism further includes extendable sides configured to be extended to and pressed against the support structure during pressing of the slab formed, thus horizontally confining the slab mixture formed during the press.

[0081] 1A16. The production plant of any one of embodiments 1A13 - 1A15, wherein the slab support structure is a mold having a flat center bounded by vertical walls, and the press mechanism further includes a surrounding gasket configured to form a seal between the mechanism of press and the vertical walls of the mold during the pressing of the slab mixture formed by the press mechanism.

[0082] 1A17. The production plant of any of embodiments 1A13 - 1A16, wherein the slab support structure is a mold having a flat center delimited by vertical walls, and said production plant further comprises at least one angled strip having two parallel joined sections forming a substantially right angle therebetween, said angled strip being configured to extend one of said sections between the formed slab mix and at least one of the vertical walls, while the other of said sections overlaps a top surface of said formed slab mix. angled strip thus forming a seal between the at least one vertical wall of the mold and the press mechanism during pressing of the formed slab mixture.

[0083] 1A18. The production plant of any of the embodiments 1A13 - 1A17, wherein the slab support structure is a mold having a flat bottom superimposed by vertical elastomeric removable walls having a first wall thickness, said walls being configured to form a seal between the flat bottom and the press mechanism during the press of the formed slab mix.

[0084] 1A19. The production plant of embodiment 1A18, wherein an interior dimension of said mold can be changed by replacing at least one of said removable walls with a wall having a second wall thickness that differs from the first wall thickness.

[0085] 1A20. The production plant of embodiment 1A18 or 1A19, wherein the elastomeric removable walls are formed of a single rectangular elastomeric shape that is configured to enclose the slab mixture formed in the mold.

[0086] 1A21. The production plant of any of embodiments 1A13 - 1A20, further comprising a plurality of slab support molds having flat centers delimited by vertical walls and a plurality of slabs configured to fit within the vertical walls of corresponding molds, said plates being attachable interchangeably for a bottom surface of a press plate included in the press mechanism, at least one dimension of the slab mixture formed being selectable from among a plurality of sizes by selecting a corresponding mold and plate from among said pluralities of molds and plates .

[0087] 1A22. The production plant of any of embodiments 1A - 1A21, further comprising a curing oven configured to heat the pressed and formed slab mix by exposing the pressed and formed slab mix to heated air.

[0088] 1A23. The embodiment 1A22 production plant, wherein the curing oven includes a cooling section configured to allow the hardened engineered stone slab to return to room temperature after curing.

[0089] A second general aspect of the present invention, referred to herein as embodiment 2A, is a production plant for forming void-free engineered composite stone slabs from a slab mixture comprising stone granules, stone dust and a resin binder, said resin binder being not more than 15% of the slab mix by weight, the production plant comprising a curing oven configured to heat a formed and pressed slab mix by exposing the formed and pressed slab mix for heated air.

[0090] A third general aspect of the present invention, referred to herein as embodiment 3A, is a press system for forming void-free engineered composite stone slabs from a slab mix comprising stone granules, stone and a resin binder, said resin binder being not more than 15% of the slab mix by weight. The press system includes a slab support structure on or in which the slab mix is deposited as a formed slab mix and a vacuum vibrating press including a vibrating table within a vacuum chamber, said vibrating table being configured to support the slab mix formed from below. Embodiment 3A further includes a press mechanism within the vacuum chamber, said press mechanism being configured to apply pressure to the slab mixture formed from above, and a sealing mechanism configured to form a seal between the press mechanism and the slab support structure.

[0091] The modalities of this third general aspect, including the following additional features:

[0092] 3A1. The press system of embodiment 3A, wherein the slab support structure is a flat structure, and the press mechanism further includes extendable sides configured to be extended into and pressed against the support structure during pressing of the formed slab mix. thus horizontally confining the slab mix formed during the press.

[0093] 3A2. The press system of embodiment 3A or 3A1, wherein the slab support structure is a mold having a flat center bounded by vertical walls, and the press mechanism further includes a surrounding gasket configured to form a seal between the press mechanism and the vertical walls of the mold during pressing the slab mix formed by the press mechanism.

[0094] 3A3. The press system of any of embodiments 3A - 3A2, wherein the slab support structure is a mold having a flat center delimited by vertical walls, and said press mechanism further comprises at least one angled strip having two parallel joined sections forming a substantially right angle therebetween, said angled strip being configured to extend one of said sections between the formed slab mix and at least one of the vertical walls, while the other of said sections overlaps a top surface of said formed slab mix. angled strip thus forming a seal between the at least one vertical wall of the mold and the press mechanism during pressing of the formed slab mixture.

[0095] 3A4. The press system of any of embodiments 3A - 3A3, wherein the slab support structure is a mold having a flat bottom superimposed by vertical elastomeric removable walls having a first wall thickness, said walls being configured to form a seal between the flat bottom and the press mechanism during the press of the formed slab mix.

[0096] 3A5. The press system of embodiment 3A4, wherein an interior dimension of said mold may be altered by replacing at least one of said removable walls with a wall having a second wall thickness that differs from the first wall thickness.

[0097] 3A6. The press system of embodiment 3A4 or 3A5, wherein the elastomeric removable walls are formed of a single rectangular elastomeric shape that is configured to enclose the slab mixture formed in the mold.

[0098] 3A7. The press system of any of embodiments 3A - 3A6, further comprising a plurality of slab support molds having flat centers delimited by vertical walls and a plurality of slabs configured to fit within the vertical walls of corresponding molds, said plates being attachable interchangeably for a bottom surface of a press plate included in the press mechanism, at least one dimension of the slab mixture formed being selectable from among a plurality of sizes by selecting a corresponding mold and plate from among said pluralities of molds and plates .

[0099] A fourth general aspect of the present invention, referred to herein as embodiment 4A, is a method for forming engineered composite stone slabs. The method includes preparing a slab mix comprising stone granules, stone powder and a resin binder, said resin binder being not more than 15% of the slab mix by weight, using a slab spreader to deposit said slab mix on or within a slab support structure as a formed slab mix, use a slab conveyor mechanism to transport said formed slab mix to a vacuum vibrating press, a portion of said slab conveyor system being directed through a passage formed between said vacuum vibrating press and a supporting floor, utilize the vacuum vibrating press to apply vacuum, pressure and vibrating energy to the slab mixture formed in a combination of amplitudes that is sufficient to compress said slab mix formed in a closed pack configuration in which all voids between the stone granules and the stone dust are filled by the r said resin binder, using said slab transport mechanism to transport said formed slab mixture pressed out of said vacuum vibrating press, curing said formed slab mixture to form an engineered stone slab, removing said slab from projected stone from said slab transport structure, and returning said slab support structure to said slab spreader.

[00100] Modalities of this fourth overview including the following additional features:

[00101] 4A1. The method of embodiment 4A, wherein returning said slab support structure to said slab spreader includes using said slab transport mechanism to return said slab support structure to said slab spreader.

[00102] 4A2. The method of embodiment 4A or 4A1, wherein the preparation of the slab mix includes using a continuous mixer to mix the stone granules, stone powder and resin binder.

[00103] 4A3. The method of any of embodiments 4A - 4A2, wherein using the slab spreader to deposit said slab mixture on or into said slab support structure includes moving the slab support structure below the slab spreader as the slab mix is deposited on or inside the slab support structure.

[00104] 4A4. The method of any of embodiments 4A - 4A3, wherein the slab support structure is a rigid tray or mold.

[00105] 4A5. The method of embodiment 4A4, wherein the slab transport mechanism includes rollers.

[00106] 4A6. The method of embodiment 4A4 or 4A5, wherein the method further includes curing the pressed slab mix formed by exposing the slab mix to heated air in a curing oven.

[00107] The features and advantages described herein are not inclusive and, in particular, many additional features and advantages will be apparent to one skilled in the art in view of the drawings, specifications and claims. Furthermore, it should be noted that the language used in the specification has been selected primarily for readability and instructional purposes and not to limit the scope of inventive matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[00108] Figure 1A is a cross-sectional illustration of stone granules, resin and voids in an engineered stone mixture prior to unopened packaging;

[00109] Figure 1B is a cross-sectional illustration of the composite stone mixture of Figure 1A after a closed package, showing resin and powder filling the entire space between the stone granules, with no voids;

[00110] Figure 1C is a flowchart illustrating the overall production process for manufacturing composite stone slabs according to the traditional prior art Breton process;

[00111] Figure 1D is a flowchart illustrating the mixing and combining of a plurality of powder, stone particles and other components having different colors and/or other different properties, in accordance with the traditional prior art Breton process;

[00112] Figure 2 is a block diagram illustrating a prior art engineered stone production plant;

[00113] Figure 3 is a cross-sectional illustration of a typical prior art PC_NC slab mix, showing excess liquid and dust completely filling the spaces between randomly oriented stone granules;

[00114] Figure 4 is a cross-sectional illustration of a vacuum vibrating press included in an embodiment of the present invention;

[00115] Figure 5A is a flowchart illustrating the steps included in producing a stone slab designed in an embodiment of the present invention;

[00116] Figure 5B is a block diagram illustrating a side view of components of the production plant used to implement the steps of Figure 5A;

[00117] Figure 6A is a block diagram illustrating a side view of components of a production plant used to mix, color and spread a slab mix in embodiments of the present invention.

[00118] Figure 6B is a top view of the components of Figure 6A;

[00119] Figure 7A is a cross-sectional side view of a press mechanism, slab, and support tray in an embodiment of the present invention in which the press mechanism includes extendable sides that are pressed down onto the support tray. during the pressing of the slab mix;

[00120] Figure 7B is a cross-sectional side view of a press mechanism, slab, and support mold in an embodiment of the present invention in which the press mechanism includes a press plate with an encircling gasket that forms a seal with the mold during pressing the slab mix;

[00121] Figure 7C is a cross-sectional side view of a press mechanism, slab, and support mold in an embodiment of the present invention including an angled strip that forms a seal between the press mechanism and the slab mix;

[00122] Figure 7D is a partial perspective view of the angled strip of Figure 7C;

[00123] Figure 8A is a top sectional view of a mold in an embodiment of the present invention having a removable flat bottom and elastomeric sides;

[00124] Figure 8B is a top sectional view of the mold of Figure 8A in which the elastomeric sides have been replaced with sides having thicker walls;

[00125] Figure 8C is a cross-sectional side view of the mold of Figure 8A shown in relation to a vibration table, cover plate and press plate;

[00126] Figure 8D is a cross-sectional side view of the mold of Figure 8B shown in relation to a vibration table, cover plate and press plate;

[00127] Figure 8E is a cross-sectional side view of a press plate having a plate attached thereto, wherein the slab size can be selected by selecting a plate and mold having corresponding sizes;

[00128] Figure 9 is a cross-sectional side view of a VVP in an embodiment of the present invention;

[00129] Figure 10 is a side view of a VVP in an embodiment of the present invention in which the slab mix is transported on a conveyor belt;

[00130] Figure 11 is a cross-sectional side view of a curing oven in an embodiment of the present invention; and

[00131] Figure 12 is a top sectional view of the curing oven of Figure 11.

DETAILED DESCRIPTION

[00132] Production plant for making engineered stone slabs and other engineered stone products costs less to manufacture and install, provides shorter press cycle times, and requires less energy consumption and maintenance compared to a production plant of engineered stone from Breton. The modalities further allow relatively easy and inexpensive exchange of aesthetic color applications and/or slab size being produced.

[00133] Referring to Figure 4, these advantages are enabled, at least in part, by features of the VVP press 400 used in embodiments of the invention, which replace the entire 350+ ton inertial base 222, 214 of the press design. Breton 208 with a light vibration table 406B below the slab 126 and a second vibration device 404B below the table, in addition to the press plate 406A and upper vibration device 404A above the slab 126. In the embodiment of Figure 4, a support of assembly 410 supports vibration table 406B and is in turn supported by vibration dampening mechanism 412 which is secured to vacuum chamber 402. Upper press plate 406A is lowered onto slab 126 and leveled by jacking jacks. screw 414, and then static pressure is applied to the slab by inflatable air pockets 408, while vibrating energy is applied by the two vibration devices 404A, 404B. By applying vibrations to the slab mix 126 from above and below the slab 126, a high percentage of the vibratory energy is directed into the slab, so that the massive base 222, 214 of the Breton press is eliminated, and a return path 418 for a conveyor belt and/or slab support trays or molds can be provided below the vacuum chamber 402. This, in turn, allows for the use of rigid, self-supporting trays or molds that can be automatically returned down the press to the mixer after the slab 132 is transferred to the curing oven.

[00134] Figure 5A is a flowchart of an embodiment of the present invention. A rigid slab support tray or mold is lifted by an elevator 500 to a level even with a roller system extending from tray elevator 500 to curing oven 514. The tray or mold is transferred on the rollers to a location below a spreader 504, which is fed by a continuous mixer 502 that prepares the slab mix. The slab mix is deposited into the tray or mold by spreader 504 and optionally color patterns are added by a rib forming station 506 while the mold is moved back and forth and side to side. This two-dimensional, horizontal movement of the tray or mold facilitates uniform deposition of the slab mix and application of a rib pattern while reducing or eliminating any need for movement of the spreader or rib forming station.

[00135] Depending on the embodiment, a cover is placed 508 on top of the slab 126. In some embodiments, the cover is a sheet of paper, a cover plate or a set of corner sheets, as described in more detail below.

[00136] Slab 126 is then transferred to VVP 510, where it is pressed and vibrated under vacuum to compress the slab mix into a closed package configuration that is free of voids. In embodiments, the tray or mold supporting the slab is transferred from the rollers to an air cushion as it is transferred to the VVP 510 and then back to the rollers as it exits the VVP 510.

[00137] After leaving the VVP 510, the slab 132 is translated vertically by a kiln elevator 512 so that it can enter a retention slot in the curing oven 514. Unlike a Breton oven, the retention slots in the oven 514 of Figure 5A there are simply spaced rollers (or in embodiment rollers on each side) that support the trays or self-supporting molds that otherwise carry the slabs 132. As a consequence, in the embodiments, air is able to flow relatively relatively free throughout the interior of the kiln, so that heated air can be used to bring all regions of all contained slabs to a constant temperature.

[00138] After curing, the slab 132 is transferred to a cooling station 516 and, after cooling, a removal elevator 518 removes the slabs 520 and transfers them to storage 522, or to a truck or other transport device. Once the slab 132 has been removed, the empty tray or mold is returned under the VVP and returned to the tray elevator 500.

[00139] Figure 5B is a simplified flowchart illustrating the interconnection between the elements of Figure 5A. In the embodiment of Figure 5B, the slab mix 126 is supported by rigid molds carried on rollers. The empty molds are lifted by the "tray" elevator 500 into position to enter the mixing area, where a continuous mixer 502 and spreader 504 deposit the slab mix into the mold. The appearance of the mixture is further improved by a rib forming station 506 and, according to the embodiment, a cover plate 508 is installed (not shown separately). The filled mold then enters the VVP 510. After being compressed, the mold is raised or lowered by the kiln elevator 512 so that it can enter one of the retaining slots in the kiln 514. After curing, the slab is cooled in a cooling station 516 (not shown separately) and then removed from mold 520 and moved to a storage location 522, while the now-empty mold is lowered by removal elevator 518 and transported on a set of return rollers below oven 514 and VVP 510 and back to "tray" elevator 500.

[00140] Figure 6A is a side view block diagram illustrating the initial portion of a production plant in an embodiment of the present invention, in which slab material is mixed and then a formed slab is prepared for input. in VVP. Figure 6B is a top view of the production plant portion shown in Figure 6A. Dry raw materials are fed from hoppers 618 to a metering and mixing device 620 and blended with resin from a resin tank 612 and optionally with dry and liquid pigment dispersions 614. Hoppers 618 are refilled from of material stored in large bulk storage tanks and silos 610, each of which, in embodiments, can hold 20 to 100 tons of material. The blended ingredients are then mixed in a continuous mixer and discharge tube 613 and deposited onto an oscillating (side-by-side) conveyor spreader arm 622. In embodiments, the conveyor spreader arm 622 is equipped with vibration devices (not shown) that help to spread and/or mix the deposited mixture.

[00141] In the embodiment of Figures 6A and 6B, the conveyor spreader arm 622 includes dispensing devices and rib-forming blades 624 that can be used to add powder or liquid pigment dispersions to the slab mix 224 as The spreader arm 622 in Figures 5 and 6 also includes rotating/oscillating mixing forks 626 that can be used to mix and match various colors or ribs for mixing 224 in a controlled manner. to get a desired look. In Figure 6A, mixing fork 626A is shown in a "down" or used position, while mixing fork 626B is shown in an "up" or unused position. The arrow shown above mixing fork 626B indicates that fork 626B can be moved with reference to fork 626A. The small boxes shown attached to mixer forks 626 in Figure 6A represent the engines and gearboxes used to drive the forks. Note that in Figure 6A the two mixing forks 626 are shown as being intertwined with each other.

[00142] When the mixture 222 reaches the end of the conveyor spreader arm 622, it is spread onto the tray or rigid support mold 600 by a spreader knife or other spreading device 606, which may be fixed or swinging, and may include features such as vibration to help evenly spread the mix to the mold or tray 600. The small arrow shown on the right side of the spreader 606 indicates the ability of the tray or mold 600 to move back and forth under the arm spreader conveyor 622 independently of movement of other trays and/or molds being processed by the production plant.

[00143] Note that in the embodiment of Figures 5A to 6B, the transport mechanism that is used to transport the trays or molds includes rollers 602 on which the trays or molds are rolled. In similar embodiments, the trays or molds are transported on a conveyor belt. In embodiments, transport mechanism 602 extends into the VVP from approximately 12 feet before spreader arm 622.

[00144] Also included in Figure 6B are dotted sketches of a second continuous mixer 613B, metering and mixing device 620B, and raw material hoppers 618B. This optional second mixer system can have a lower capacity (20-150 kg per minute) than the primary system, and also the ability to change the color of the output material quickly (e.g. every 2-10 seconds), allowing thus mixing 2-5 different colors of the 224 slab mix to produce a multicolored, possibly ribbed, result like a granite-like appearance. In embodiments, these continuous mixer systems can be completely cleaned and changed to a new color (by a technician) in about 20 minutes, with the loss of only about 10-20 kg of material.

[00145] Once the formed slab mixture 126 has entered the VVP 510, it must be pressed and vibrated without distorting its slab shape. Figure 7A is a cross-sectional side view of an embodiment in which the slab mix 126 is supported by a rigid tray 700. In embodiments, the tray 700 is a rigid sheet of material that may be made, for example, of metal. , plastic, or a composite. The tray 700 fully supports the slab mix 126 as it is transported in and out of the spreader area 500, the VVP 510, and the curing oven system 514. In the embodiment of Figure 7A, the mix rests on a Bottom paper liner 702 and a second paper liner covers the mixture 126 from above 704. Upper press plate 406A includes downwardly extending sides 706 driven by springs 708. When press plate 406A is lowered onto slab 126 , the extensible sides 706 are pressed down by the springs 708 against the tray 700, causing the top skin 704 to be wrapped around the sides of the slab 126. Accordingly, during pressing and vibration, the top skin 704 forms a seal between tray 700, side walls 706 and press plate 406A, and prevents any of the slab mixes 126 from being squeezed through gaps in the mechanism.

[00146] Typically, tray 700 is about 1-4 inches wider than press plate 406A and side walls 706 on all sides so that it can accommodate inner paper layers 702 and upper 704, the sidewalls 706 of press plate 406A and/or rubber sidewalls, as discussed in greater detail with reference to Figures 8A to 8D below.

[00147] Figure 7B is a sectional view of a similar embodiment in which the slab mix 126 is supported within a rigid mold 600. In this embodiment, the slab mix 126 is covered by a rigid cover plate 710 and a seal. is formed between upper press plate 406A and mold 600 by a gasket 712 which surrounds upper press plate 406A. Cover plate 710 and/or mold 600, as well as tray 700 of Figure 7A, can be made of any rigid material that can withstand temperatures up to 100 degrees C or more, which is the nominal temperature of curing oven 514. The material must be able to remain rigid during movement along a roller-based conveyor system 602 and oven 614. The mold material must also not adversely dampen the vibratory energy of the VVP 510. In various embodiments, the material selected is steel. polished stainless steel, anodized aluminum (hard coating, black aluminum with or without first polishing the surface before anodizing), or other metal, fiberglass, fiber reinforced resin, ceramic or glass. Tray 700 or mold 600 can be treated with a release agent that is appropriate for the resin used in slab mix 126, which can eliminate the need for sheets of paper above and below slab 126.

[00148] Figure 7C is an enlarged cross-sectional illustration of an embodiment similar to Figure 7B except that a right angle strip 714 is used to form a seal between the sides of the mold 600 and the press plate 406A. The right angle strip 714 in the embodiment of Figure 7C is placed around the perimeter of the slab mix 126, just inside the walls of the mold 600, and forms a seal in a similar manner to the top paper cover 702 of Figure 7A, except that less material is needed, thus reducing weight and cost. The right angle strip can be made of paper, thin plastic or even thin metal. It is typically about 1-2" wide on each side, and long enough to extend over the entire perimeter of the slab. Figure 7D is an enlarged perspective view of paper corner 714 of Figure 7C.

[00149] Figure 8A is a top sectional view of an embodiment in which the slab mix 126 is supported by a tray 700 and bounded by a wall 800A made from an elastomer, such as a rubber or other material. little compressible. The combined tray 700 and wall 800A work together in a similar manner to the mold 600 of Figure 7B. To make a "jumbo" slab (an industry standard size since 2009, about 132" long by 62" wide), the 800A bounding wall is only about 2-3" wide.

[00150] As illustrated in Figure 8B, this embodiment easily accommodates a change in the size of slab 126 (e.g. to make a "standard" size slab, which has been a standard since 2002 and is still widely used in the industry) simply switching to a different 800B wall that has an increased width. The height of rubber wall 800A, 800B is also adjusted according to the desired slab thickness 126, for example, from 1cm to 2cm to 3cm thick, etc.

[00151] As illustrated in the side view of Figure 8C, the elastomeric wall 800A makes a seal with the top press plate 406A or cover plate 710 (if used), and is compressed as pressure is applied to the mixture of slab 126. Consequently, there is no need for a covering paper 704, gasket 712, right angle strip 714 or any other special seal forming mechanism. As shown in the side view of Figure 8D, the only component that needs to be changed to change the size of the slab is the 800B rubber wall itself.

[00152] Figure 8E is a cross-sectional side view of a mold 600 and press plate 406A in an embodiment that allows for an easy transition between different slab sizes when the slabs 126 are contained in rigid molds 600 rather than transported. in trays 700. In this embodiment, upper press plate 406A is adapted to smaller mold sizes 600 by attaching a special plate 802 to the underside of press plate 406A, using screws 804, or by some other reversible attachment mechanism. In the embodiment of Figure 8E, the bottom of the standard size mold 600 extends beyond the sides of the mold so that it can be correctly positioned as if it were a "jumbo" mold. The location of side walls 806 for a "jumbo" mold 600 is shown in dashed lines in the figure. When a jumbo mold 600 is to be used, then the plate 802 is removed, and a different size plate 802 is installed, or the press plate 406A itself is used without a plate 802. In these embodiments, a seal between the press plate 406A and mold 600 may be formed by any of the mechanisms shown in Figures 7B to 7D, or by some other means.

[00153] Figure 9 is a cutaway side view of a VVP 400 in an embodiment of the present invention. In this embodiment, the vacuum chamber 402 is cylindrical with rounded end caps similar to a compressed air tank, which is strong, lightweight, and easy to manufacture. Other embodiments include vacuum chambers having other shapes. The entire device in the embodiment of Figure 9 sits between four and six legs 416, and is lifted off the floor a distance of between 8 and 15 inches to provide space for empty molds 600B to automatically return to the mixing station on the conveyor track. of return roller 602B running beneath the vacuum chamber 402.

[00154] The vacuum chamber 900 is divided into upper and lower sections which are joined by precision milled flanges 902, 904 vacuum sealed together by an "O" ring (not shown) or other sealing mechanism known in the art. This is necessary for the top section to be removed for maintenance and assembly.

[00155] The two halves of the vacuum chamber 900 are not separated during normal pressure operations. Instead, the slab mix 126 enters and leaves the vacuum chamber 900 through openings that are covered by vacuum sealable ports, which are shown in the figure with solid lines in the closed position 906 and with dashed lines in the open position 908. Typically these openings are about 8-10" high and (for a "jumbo" sized slab) about 72" wide, to allow entry and exit of slab 126 with tray 700 or mold 600 In the embodiment of Figure 9, the slab mix 126 is conveyed to the vacuum chamber in a mold 600 supported by rollers 602A. Once the mold 600 reaches the vibration table 406B, it is transferred from the rollers to an air dampening support plate 920 which is permanently attached to the vibration table 406B, as can be seen in the expanded detail 924. dampening support bracket 920, which may be metal or plastic, includes small holes 922 that emit pressurized air to support the mold as it is transferred to vibration table 406B, and as it is removed after the press.

[00156] Cutout portion 900 of Figure 9 reveals the vibrating press device and other components that are within the vacuum chamber 900. In the embodiment of Figure 9, the vibrating table 406B supports two or more "bridges" permanently attachments 910 comprising vertical columns 912, connected on either side of the vibration table 406B by transverse beams 914, to which air pockets 408 are attached that apply downward pressure on the top press plate 406A. The top press plate 406A is raised and lowered by precision screw jacks 414 or other suitable device that controls the height of the top press plate 406A relative to the vibrating table 406B so that the thickness of the pressed slab 132 can be precisely controlled. In various embodiments, at least one jackscrew 414 is located near each corner of the top press plate 406A.

[00157] In the embodiment of Figure 9, the vibration table 406B, bridges 910, and top vibrating press plate 406A (attached to the bridges by pressure air pockets 408) are supported by lower vibration suppression air pockets 916 which are attached to the interior of the vacuum chamber 402 by the brackets 918. In similar embodiments, other vibration dampening mechanisms, such as springs, are used. Consequently, the vibration energy of the vibration table 406B and the top vibration press plate 406A is isolated from the vacuum chamber 402, and therefore from the floor 216 and the surrounding environment.

[00158] Figure 10 is a side view of an embodiment in which a conveyor belt 1000 is used instead of rollers and an air cushion is used to transport the slab mix 126 to the vacuum chamber 402 and the pressed slab 132 out. of the vacuum chamber 402. Conveyor belt 1000 can be used to convey slab mixes 126 deposited on sheets of paper and rubber molds, as are used in traditional Breton presses 208, or can be used to transport rigid trays 700 or molds 600 as described here.

[00159] Figure 11 is a cutaway side view of a curing oven 514 in an embodiment of the present invention. After being raised or lowered into position by oven elevator 512, tray 700 or mold 600 enters one of holding levels 1212 in oven 514, which can be seen through cutout 1210. The oven is surrounded by walls. thermally insulated 1200. Inside the walls 1200 is a chamber 1202, which is visible in the figure by means of the cutout 1204. The chamber 1202 is penetrated by a plurality of holes 1206, which allow hot air supplied by ducts 1208 to enter the interior. oven 514 and flow past and around molds 600 containing curing slabs 132. After curing is complete, the mold exits oven 514, passes through a staging region 1214, and enters a cooling section. 516 where it slowly returns to room temperature.

[00160] Figure 12 is a top cutaway view of the oven of Figure 11. Visible in the figure is a central duct 1216 supplying hot air to the individual ducts 1208, which then distribute the hot air to chamber 1202.

[00161] The foregoing description of embodiments of the invention has been presented for the purposes of illustration and description. Each and every page of this presentation, and all content therein, however characterized, identified, or numbered, is considered a substantial part of this application for all purposes, regardless of form or placement within the application.

[00162] This specification is not intended to be exhaustive. Although the present patent application is shown in a limited number of forms, the scope of the invention is not limited to these forms only, but is susceptible to various alterations and modifications without departing from the spirit thereof. One of ordinary skill in the art should appreciate after learning the teachings relating to the claimed subject matter contained in the foregoing description, that many modifications and variations are possible in light of the present disclosure. Accordingly, the subject matter claimed includes any combination of the elements described above in all possible variations thereof, unless otherwise indicated herein or otherwise clearly contradicted by context. In particular, the limitations set forth in the dependent claims below may be combined with their corresponding independent claims in any number and in any order, without departing from the scope of the present disclosure, unless the dependent claims are logically incompatible with each other.

Claims (23)

1. Production plant for the formation of engineered composite stone slabs, the production plant CHARACTERIZED by the fact that it comprises: a vacuum vibrating press capable of applying vacuum, pressure and vibratory energy to a formed slab mixture deposited on or within a slab support structure, said slab mix comprising stone granules, stone powder and a resin binder, said resin binder being no more than 15% of the slab mix by weight, said vacuum, pressure and vibratory energy being applied in a combination of amplitudes that is sufficient to compress said slab mixture formed into a closed pack configuration wherein all voids between the stone granules and the stone powder are filled by said resin binder, said press vibrating vacuum press being suspended above a supporting floor, so that a passage is provided between said vacuum vibrating press and said floor of s support; and a slab transport system configured to transport said formed slab mixture into and out of said vacuum vibrating press, a portion of said slab transport system being directed through said passage formed between said vibrating press and vacuum and said supporting floor; wherein the vacuum vibrating press comprises: a vibrating table within a vacuum chamber, said vibrating table being configured to support the slab mix formed from below; a press mechanism within the vacuum chamber, said press mechanism being configured to apply pressure to the slab mixture formed from above; at least one lower vibration device cooperative with the vibration table; and at least one upper vibration device cooperative with said press mechanism. 2. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab transport system includes a conveyor belt that extends through said vacuum vibrating press and returns through said passage between said vibrating press to vacuum and said support floor. 3. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab transport system is configured to allow the slab support structure to move in at least two orthogonal directions while the slab mix is deposited on or within the slab support structure. 4. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab transport system includes rollers on which the slab support structure can be rolled, said rollers including rollers that allow said support structure of slab, after the removal of said projected stone slab, is rolled down said vacuum vibrating press in preparation for deposition of slab mix on or within the slab support structure. 5. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab transport system is configured to allow a plurality of slab support structures to move independently of each other in at least one horizontal direction. 6. Production plant, according to claim 1, CHARACTERIZED in that it further comprises a continuous mixer configured to prepare said slab mixture by mixing together said stone granules, stone powder and resin binder. 7. Production plant, according to claim 6, CHARACTERIZED by the fact that said continuous mixer can produce up to 100 kg per minute of slab mix. 8. Production plant, according to claim 6, CHARACTERIZED by the fact that said continuous mixer can produce up to 300 kg per minute of slab mix. 9. Production plant, according to claim 1, CHARACTERIZED in that it further comprises an air dampening mechanism configured to support the slab mixture formed as it is transported in and out of the vacuum vibrating press . 10. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab transport system includes at least one slab lift configured to adjust a height of the slab transport system above the supporting floor. 11. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab support structure is a sheet of paper or an elastomeric mold. 12. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab support structure is a mold having a flat center delimited by vertical walls, and said production plant also comprises a rigid cover plate configured to placing the formed slab mix on top of said vertical walls during pressing of the formed slab mix. 13. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab support structure is a rigid tray or a rigid mold. 14. Production plant, according to claim 1, CHARACTERIZED in that it further comprises a flexible cover sheet configured to overlap the formed slab mixture and form a seal between the slab support structure and the press mechanism during the press of the formed slab mix. 15. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab support structure is a flat structure, and the press mechanism also includes extendable sides configured to be extended to and pressed against the support structure during pressing the slab mix formed, thus horizontally confining the slab mix formed during the pressing. 16. Production plant, according to claim 1, CHARACTERIZED by the fact that the slab support structure is a mold having a flat center delimited by vertical walls, and the press mechanism also includes a surrounding joint configured to form a sealing between the press mechanism and the vertical walls of the mold during the pressing of the slab mixture formed by the press mechanism. 17. Production plant, according to claim 1, CHARACTERIZED in that the slab support structure is a mold having a flat center delimited by vertical walls, and said production plant further comprises at least one angled strip having two parallel joined sections forming a substantially right angle therebetween, the angled strip being configured to extend one of said sections between the formed slab mix and at least one of the vertical walls, while the other of said sections overlaps a top surface of the formed slab mix. formed slab, said angled strip thus forming a seal between the at least one vertical mold wall and the press mechanism during pressing of the formed slab mixture. 18. Production plant, according to claim 1, CHARACTERIZED in that the slab support structure is a mold having a flat bottom superimposed by vertical elastomeric removable walls having a first wall thickness, said walls being configured to form a seal between the flat bottom and the press mechanism during the pressing of the formed slab mix. 19. Production plant according to claim 18, CHARACTERIZED in that an interior dimension of said mold can be altered by replacing at least one of said removable walls with a wall having a second wall thickness that differs from the first thickness of Wall. 20. Production plant, according to claim 18, CHARACTERIZED by the fact that the elastomeric removable walls are formed by a single rectangular elastomeric shape that is configured to envelop the slab mixture formed in the mold. 21. Production plant, according to claim 1, CHARACTERIZED in that it further comprises: a plurality of slab support molds having flat centers delimited by vertical walls; and a plurality of plates configured to fit within the vertical walls of corresponding molds, said plates being interchangeably attachable to a bottom surface of a press plate included in the press mechanism; at least one dimension of the formed slab mix may be selected from a plurality of sizes by selecting a corresponding mold and plate from among said plurality of molds and plates. 22. Production plant, according to claim 1, CHARACTERIZED in that it further comprises a curing oven configured to heat the formed and pressed slab mixture by exposing the formed and pressed slab mixture to heated air. 23. Production plant, according to claim 22, CHARACTERIZED in that the curing oven includes a cooling section configured to allow the hardened engineered stone slab to return to room temperature after curing.

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