Synthetic molded slabs, and systems and methods related thereto

This document describes systems and processes for forming synthetic molded slabs, which may be suitable for use in living or working spaces (e.g., along a countertop, table, floor, or the like).

TECHNICAL FIELD

This document describes systems and processes for forming synthetic mold slab products, for example, a synthetic mold slab that is thermoformed or otherwise compacted to a selected slab shape from a mixture including particulate mineral material, resin binder, and pigments so that the synthetic molded slab is suitable for use in living or working spaces (e.g., along a countertop, table, floor, or the like).

BACKGROUND

Quarried stone slabs are a commonly used building material. Granite, marble, soapstone, and other quarried stones are often selected for use as countertops due to their aesthetic properties. Despite the visual appeal of quarried stone, quarried stones can be quite expensive to obtain and are generally limited to naturally occurring color schemes.

Engineered stone slabs may be formed from a man-made combination of materials that can provide improved stain-resistant or heat-resistant properties compared to quarried stone. Engineered stone is typically a combination of particulate mineral material and binder, such as a polymer resin or cement. Some engineered stones partly emulate some aesthetic properties of quarried stone, but still fall noticeably short of the complicated look and texture of quarried stone.

SUMMARY

Some embodiments described herein include systems and processes for forming synthetic molded slabs suitable for use in living or working spaces (e.g., along a countertop, table, floor, or the like). In particular embodiments, the synthetic molded slabs can be manufactured using, for example, a set of stencils that separate differently pigmented particulate mineral mixes into predetermined regions of a series of molds, thereby providing molded slabs having a similar appearance to one another (which, unlike quarried stone slabs taken from a quarry, can be generally repeatable and predefined as part of the manufacturing process). As used herein, “differently pigmented” means having different pigment combinations or otherwise having a different visual apparent in color tone or visual texture. In such embodiments, however, the appearance of each synthetic molded slab can provide the complex striations and veining patterns that emulate a quarried stone slab. For example, each slab can be formed from a combination of differently pigmented particulate mineral mixes that are separately dispensed into two or more partial molds which combine to facilitate the selected striations and veining patterns. The slabs may be subsequently processed by compression molding and curing operations.

Particular embodiments described herein include a process of forming a synthetic molded slab from different particulate mineral mixes. The process may include sequentially dispensing at least first and second pigmented particulate mineral mixes comprising predominantly a quartz material into a single slab mold using at least first and second distributors. The first distributor may output the first pigmented particulate mineral mix through a first stencil positioned over the slab mold and into the slab mold according to a first stencil pattern, and the second distributor may subsequently output the second pigmented particulate mineral mix through a second stencil positioned over the slab mold and into the slab mold according to a second stencil pattern such that the second pigmented particulate mineral mix is deposited in regions of the slab mold that are unoccupied by the first pigmented particulate mineral mix. The process may further include vibrating and/or compacting the pigmented particulate mineral mixes arranged in the slab mold so as to form a synthetic molded slab that is generally rectangular and has major surface. In various embodiments, the major surface may have a width or at least 3 feet and a length of at least 6 feet. Optionally, the aforementioned vibrating and compacting of the pigmented particulate mineral mixes arranged in the slab mold may be performed contemporaneously. Additional embodiments described herein include a synthetic molded slab formed according to this particular process.

Some embodiments described herein include a process of forming a synthetic molded slab from a set of different particulate mineral mixes that each include a quartz material, one or more pigments, and one or more resin binders. The process may include outputting a first particulate mineral mix of the set of different particulate mineral mixes from a first distributor and through a first stencil that is positioned over a slab mold and that defines a first pattern of first design apertures surrounded by first occluded regions. The process may further include depositing the first particulate mineral mix passing through the first design apertures into the slab mold so as to partly fill a mold space of the slab mold that is at least 6 feet long by at least 3 feet wide. The process may also include moving the partly filled slab mold relative to the first stencil so that a second stencil is positioned over the partly filled slab mold, and the second stencil may define a second pattern of second design apertures surrounded by second occluded regions. The process may further include outputting a second particulate mineral mix of the set of different particulate mineral mixes from a second distributor and through the second design apertures of the second stencil. Also, the process may include depositing the second particulate mineral mix passing through the second design apertures into the slab mold and into regions of the mold space of the slab mold that are unoccupied by the first pigmented particulate mineral mix. Further, the process may include vibrating and compacting (which are optionally performed contemporaneously) the pigmented particulate mineral mixes arranged in the slab mold so as to form a synthetic molded slab that is generally rectangular and has major surface with a width or at least 3 feet and a length of at least 6 feet. Additional embodiments described herein include a synthetic molded slab formed according to this particular process.

In one aspect of this process, the first particulate mineral mix and the second particulate mineral mix may comprise at least two differently colored mineral mixes that each include the quartz material, one or more pigments, and at least one binder. In second aspect of this process, the depositing of the first particulate mineral mix may include distributing the first particulate mineral mix according to a first predefined pattern, and the depositing the second particulate mineral mix may include distributing the second particulate mineral mix according to a second predefined pattern. In a third aspect of this process, the first predefined pattern may define a first pigmented vein, and the second predefined pattern may define a second pigmented vein of the slab. In a fourth aspect of this process, at least a portion of the first pigmented vein may surround at least a portion of the second pigmented vein. In a fifth aspect, the process may further include polishing the major surface of the slab. In a sixth aspect, the process provides the slab in a manner that emulates the appearance of a quarried stone slab due at least in part to the two differently colored mineral mixes distributed according to the first predefined pattern and the second predefined pattern. In a seventh aspect of this process, the depositing the first particulate mineral mix may include depositing the first particulate mineral mix into the slab mold according to a first predefined and repeatable pattern, and the depositing the second particulate mineral mix may include depositing the second particulate mineral mix into the slab mold according to a second predefined and repeatable pattern so as to define complementary regions of multiple different particulate mineral mixes.

Further embodiments described herein include a system for forming a synthetic molded slab using a combination of different particulate mineral mixes. The system may include at least one slab mold defining a mold space that is at least 6 feet long by at least 3 feet wide. Also, the system may include two or more stencils defining complementary patterns of open spaces and occluded spaces, and the cumulative areas of the open spaces of the stencils corresponding to substantially the mold space of the particular slab mold. The system may further include two or more mineral aggregate distributors that are each configured to dispense a corresponding particulate mineral mix into the slab mold through a corresponding one of the stencils. Each stencil may be configured to prevent a mix in the distributor from accessing selected areas of each mold in the series of molds.

Some embodiments described herein include a set of separately molded synthetic slabs having a substantially repeated rectangular major surface appearance defined by a set of particulate mineral mixes. Each respective slab of the set may include at least two different particulate mineral mixes distributed according to at least two predefined stencil patterns for each of the synthetic slabs in the set of separately molded synthetic slabs. A first mix of the at least two different particulate mineral mixes occupies a full thickness each respective slab at first regions in which a second mix of the at least two different particulate mineral mixes is absent, and the second mix of the at least two different particulate mineral mixes occupies the full thickness of each respective slab at second regions in which the first mix of the at least two different particulate mineral mixes is absent. Optionally, the at least two different particulate mineral mixes may each comprise a quartz material, one or more pigments, and one or more resin binders. Also, each respective slab is rectangular and has major surface with a width or at least 3 feet and a length of at least 6 feet.

Particular embodiments described herein include a synthetic molded slab that optionally comprises at least a quartz material. The synthetic molded slab may include a major surface defined by a set of particulate mineral mixes and having a rectangular shape that is at least 2 feet wide by at least 6 feet long and extending perpendicularly to a slab thickness. The major surface may have at least a first pigmented vein pattern defined by a first stencil pattern and a second pigmented vein pattern defined by a second stencil pattern that is a negative of the first stencil pattern. The first pigmented vein pattern may include a first particulate mineral mix that occupies the slab thickness at a set of first regions that collectively provide the first pigmented vein pattern, and the second pigmented vein pattern may include a second particulate mineral mixes that occupies the slab thickness at a set of second regions that collectively provide the second pigmented vein pattern. The first particulate mineral mix may be absent from the set of second regions, and the second particulate mineral mix may be absent from the set of first regions. The first and second particulate mineral mixes may be differently pigmented, and each of the particulate mineral mixes may optionally comporise the quartz material, one or more pigments, and one or more binders.

The systems and techniques described here may provide one or more of the following advantages. First, a system can be used to produce a plurality of synthetic molded slabs that each have similar striations and veining patterns and that are suitable for use in living or working spaces (e.g., along a countertop, table, floor, or the like). Such slabs can be formed from a combination of differently pigmented particulate mineral mixes that are vertically distributed into designated regions of each mold according to predefined and complementary dispensation patterns (e.g., two or more horizontally oriented templates that can be positioned over each mold), which provide the selected striations and veining patterns that are generally repeatable for each separately molded slab.

Second, each slab in the system can be formed from a compression molding operation in which the molds containing the particulate mineral mixes are maintained in a horizontal orientation after the mold is filled. For example, the differently pigmented particulate mineral mixes are vertically poured through a series of complementary, horizontally oriented templates, the filled mold is shifted horizontally for a subsequent compression molding operation (e.g., vibro-compaction molding, curing, etc.). From there, some or all of the mold is removed from the hardened slab so that at least a major surface of the slab is polished to provide an appearance of the complex striations and veining patterns that emulate a quarried stone slab. In such circumstances, the polished major surface of each of the synthetic molded slabs provides an outer appearance that is remarkably similar to the other slabs in the set of separately molded slabs, unlike quarried stone slabs taken from a quarry. Moreover, the pigments and particulate mineral mixes can be selected to provide color combinations and visual effects that improved upon and offer a variety of color combination options far beyond what is available from quarried stone slabs taken from a quarry.

DETAILED DESCRIPTION

Referring toFIG. 1, a system can be used to produce one or more synthetic molded slabs50having a number of striations or veins according to a predefined pattern. Each slab50can comprise a quartz material and/or other particulate mineral material that, when mixed with pigments and a resin binder and compressed, provides a hardened slab product suitable for use in living or working spaces (e.g., along a countertop, table, floor, or the like). As shown inFIG. 1, each slab50can be formed from a combination of differently pigmented particulate mineral mixes that are vertically poured into different, designated regions of a respective mold (while the mold is horizontally oriented in this embodiment). These designated regions are repeated for each mold in a series of molds (described in more detail below) due to, for example, a set of stencil structures that can be positioned over each mold and that provide a predefined complementary and repeatable dispensation pattern for the differently pigmented particulate mineral mixes in each mold. In some embodiments described herein, the predefined complementary and repeatable dispensation pattern for the differently pigmented particulate mineral mixes provides the selected striations and veining patterns that are generally repeatable for each separately molded slab. As will be discussed in further detail in the descriptions ofFIGS. 2A-7, some embodiments described herein employ a first partial stencil is arranged above a horizontal slab mold, and a first pigmented particulate mix is dispensed though open portions of the stencil into the mold. One or more successive stencils (e.g., at least a second partial stencil) are positioned over the same mold that is partially filled with the first pigmented particulate mix in predefined regions, and one or more differently pigmented particulate mixes (e.g., at least a second pigmented particulate mix) are sequentially dispensed through open portions of the successive stencils into the mold until all regions of the mold are filled. The mold may be subsequently transported in the horizontal orientation for compaction, curing, and other operations.

As shown inFIG. 1, depending upon the predefined dispensation pattern of the complementary partial stencils, the dispensation process can provide an aesthetic effect that emulates the veined appearance of natural quarried stone slabs such as granite or marble, including some veins51and52that extend partly or fully across a complete length L of the hardened slab50(e.g., at least 3 feet wide by at least 6 feet long, and between about 3 feet and 6 feet wide and between about 6 feet and 12 feet long, between about 4.5 feet and 5.5 feet wide and between about 10 feet and 11 feet long, and preferably a size selected from one of about 4.5 feet wide by about 10 feet long or about 5.5 feet wide by about 11 feet long). Not only can such differently pigmented veins51and52extend across the full length of the slab product, but such veins51and52can also extend through the thickness of the slab50(thereby providing a natural vein appearance even when the slab is cut and edged to specific shapes in living or working spaces (e.g., along a countertop, table, floor, or the like). Because each slab50in the set of separately molded slabs can include the layers of different particulate mineral mixes dispensed into the mold according to the predefined and repeatable dispensation patterns of complementary stencils, multiple slabs50in the set of separately molded slabs can have substantially the same appearance to one another.

In this embodiment depicted inFIG. 1, the slab50comprises two different particulate mineral mixes that are separately dispensed into the mold130through two complementary stencils (e.g., a first stencil that is essentially a negative of a second stencil). However, in some embodiments, three or more stencils may be used to repeatably pattern the distribution of three or more different particulate mineral mixes that are separately dispensed into the mold130. The different mixes dispensed into each mold according to the repeatable pattern can be compaction molded and cured in the mold (described in more detail below) so as to provide the hardened slab50of composite stone material. One or more of the mixes that are used to form the composite stone material can include organic polymer(s) and inorganic (mineral) particulate component. The inorganic (mineral) particulate component may include such components as silicon, basalt, glass, diamond, rocks, pebbles, shells, a variety of quartz containing materials, such as, for example, but not limited to: crushed quartz, sand, quartz particles, and the like, or any combination thereof. In this embodiment, all of the different particulate mineral mixes each comprise a quartz material as a predominant component, which may include sand of various particle sizes and of different combinations. In the hardened slab50, the organic and inorganic materials can be linked using a binder, which may include for example, mono-functional or multifunctional silane molecules, dendrimeric molecules, and the like, that may have the ability to bind the organic and inorganic components of the composite stone mix. The binders may further include a mixture of various components, such as initiators, hardeners, catalysators, binding molecules and bridges, or any combination thereof. Some or all of the mixes dispensed in the mold may include components that are combined in a mixing apparatus (not shown) prior to being conveyed to the mold. The mixing apparatus can be used to blend raw material (such as the quartz material, organic polymers, unsaturated polymers, and the like) at various ratios. For example, some or all of the mixes dispensed in the mold may include about 8-95% quartz aggregates to about 5-15% polymer resins. In addition, various additives, may be added to the raw materials in the mixing apparatus, such additives may include, metallic pieces (e.g., copper flecks or the like), colorants, dyes, pigments, chemical reagents, antimicrobial substances, fungicidal agents, and the like, or any combination thereof.

Preferably, the mold at least partially defines a length L and a width W of the hardened slab50(because the mold retains the particulate mineral mixes therein throughout the subsequent compaction and curing processes). In some embodiments, the width W of the slab50formed in the mold is at least 3 feet, between about 3 feet and 6 feet, and preferably about either 4.5 feet, and the length L of the slab50formed in the mold is at least 6 feet, and between about 6 feet and 12 feet, preferably about 10 feet. In some implementations, the mold may be sized to form larger (e.g., “jumbo”) slabs, where the width W of the slab50formed in the mold is about 5 feet to about 6 feet (e.g., preferably about 5.5 feet) and the length L of the slab50formed in the mold is about 10.5 feet to about 12 feet (e.g., preferably about 11 feet). As such, even though each slab50can be relatively large in length L, some or all of the veins51,52can nevertheless extend across the full length of the slab50. In some embodiments, the thickness T of the slab50formed is at least 1 inch, between about 1 inch and 5 inches, and preferably about 3 inches.

Referring now toFIGS. 2A and 2B, exploded and assembled views of an example of a first partial slab stencil200. Referring toFIG. 2A, a slab mold130and the partial slab stencil200are shown in an exploded and inverted view. The slab mold130includes a planar mold floor132bounded by a collection of mold walls131extending perpendicular from the planar mold floor, defining a generally tray-like shape.

The partial slab stencil200includes an outer frame202having a length and width that approximates that of the slab mold130. In some embodiments, the slab mold130can be at least 3 feet, between about 3 feet and 5 feet, and preferably about 4 feet, and the length L of the slab50formed in the mold is at least 6 feet, and between about 6 feet and 10 feet, preferably about 8 feet. In some implementations, the slab mold may be sized to form larger (e.g., “jumbo”) slabs, where the width W of the slab50formed in the mold is at least 5 feet (e.g., about 5.5 ft) and the length L of the slab50formed in the mold is at least 10 feet (e.g., about 11 ft). In some embodiments, the slab mold130can have a thickness T of at least 1 inch, between about 1 inch and 5 inches, and preferably about 3 inches.

The outer frame202that supports a collection of occluded regions204and defines a collection of design apertures206. The outer frame202and/or the occluded regions204can be formed from metal (e.g., steel, aluminum), plastic, wood, composite (e.g., fiberglass, carbon fiber), rubber, or combinations of these and/or any other appropriate material. In some embodiments, the outer frame202and/or the occluded regions204can include non-stick materials or coatings that can resist adhesion with the ingredients of particulate mineral mixes.

The occluded regions204extend beyond the outer frame202a distance approximately equal to the thickness T of the slab mold103. When the partial slab stencil200is assembled with the slab mold130, as shown inFIG. 2B, the outer frame202rests upon the mold walls131of the slab mold130, and the occluded regions204extend substantially through the thickness T of the slab mold130to contact the planar mold floor132. As will be discussed further in the descriptions ofFIGS. 4-7, when the partial slab stencil200is assembled with the slab mold130, the design apertures206define spaces within the slab mold into which a particulate mineral mix can be dispensed, while the occluded regions204prevent the mix from entering.

Referring now toFIGS. 3A and 3B, exploded and assembled views of an example of a second partial slab stencil300. Referring toFIG. 3A, the same slab mold130(previously depicted inFIGS. 2A and 2B) and the second partial slab stencil300are shown in an exploded and inverted view. Generally speaking, in this embodiment, the second partial slab stencil300is complementary to the first partial slab stencil200(FIGS. 2A and 2B). For example, areas that are occluded in the first partial slab stencil200are generally open in the second partial slab stencil300, and areas that are open in the first partial slab stencil200are generally occluded in the second partial slab stencil300. In some embodiments, the first partial slab mold200may define a “positive” pattern while the second partial slab stencil300defines a “negative” pattern that corresponds inversely to the “positive” pattern.

The second partial slab stencil300includes an outer frame302having a length and width that approximates that of the slab mold130. The outer frame302that supports a collection of occluded regions304and defines a collection of design apertures306. The outer frame302and/or the occluded regions304can be formed from metal (e.g., steel, aluminum), plastic, wood, composite (e.g., fiberglass, carbon fiber), rubber, or combinations of these and/or any other appropriate material. In some embodiments, the outer frame302and/or the occluded regions304can include non-stick materials or coatings that can resist adhesion with the ingredients of particulate mineral mixes.

The occluded regions304extend beyond the outer frame302a distance approximately equal to the thickness T of the slab mold103. When the second partial slab stencil300is assembled with the slab mold130, as shown inFIG. 3B, the outer frame302rests upon the mold walls131of the slab mold130, and the occluded regions304extend substantially through the thickness T of the slab mold130to contact the planar mold floor132. As will be discussed further in the descriptions ofFIGS. 4-7, when the second partial slab stencil300is assembled with the slab mold130, the design apertures306define spaces within the slab mold130into which a particulate mineral mix can be dispensed, while the occluded regions304prevent the mix from entering. In some embodiments, three or more partial slab stencils with design apertures that cumulatively correspond substantially to the length and width of the slab mold can be used (for sequentially dispensing a corresponding number of differently pigmented particulate mixes).

Referring now toFIG. 4, in some embodiments, a system400for forming a set of synthetic molded slab products (e.g., the slab50inFIG. 1) is configured to sequentially dispense differently pigmented particulate mineral mixes through two or more complementary partial slab stencils and into the same horizontally oriented mold, which is then processed using a subsequent compression molding operation (e.g., vibro-compaction molding, curing, etc.). The system400in the depicted embodiment includes an input conveyor410and an output conveyor420. A collection of slab molds130are transported on the input conveyor410. The slab molds130provide a form for synthetic molded slab products that are at least three feet wide and at least six feet long. The input conveyor410transports the slab molds130to an air table440. The air table440includes a collection of outlets formed on a top surface. Air pumped through the outlets forms a cushion of air between the top surface and the slab molds130, to help operators move and/or orient the slab molds130.

Still referring toFIG. 4, the system400also includes a collection of mineral aggregate distributors460a,460b. In this embodiment, each of the distributors460a,406bis dedicated to dispensing a corresponding particulate mineral mix (refer toFIG. 1). In this embodiment, the partial slab stencil200is temporarily assembled to the slab mold130. The slab mold130is moved horizontally (e.g., relative to gravity) beneath the distributor460a, partly filling the slab mold130with a first particulate mineral mix. The partial slab stencil200is disassembled from the slab mold130, and the partial slab stencil300is temporarily assembled to the partly filled slab mold130. The slab mold130is moved horizontally (e.g., relative to gravity) beneath the distributor460b, partly filling the slab mold130(e.g., the complementary areas left unfilled by the partial slab stencil200) with a second particulate mineral mix. Additional details of this particular embodiment of the partial slab stencils200,300are described further in connection withFIGS. 5A-7.

For example, in this embodiment, the first and second partial slab stencils200,300are configured to receive two differently pigmented mineral mixes (comprising mostly a quartz material as described above), so there are two corresponding distributors460a,406b. In this embodiment, each of the mineral aggregate distributors460a,460bincludes a dispensing head462. In use, the dispensing heads462each receive a corresponding particulate mineral mix from a different mixer line (not shown), such that each dispenser head462is configured to release a different particulate mineral mix (e.g., different pigments, different mineral compositions, different additives, or a combination thereof) compared to the other dispenser heads462. Each dispenser head462is configured to controllably dispense its supply of corresponding particulate mineral mix through the apertures206,306of a corresponding one of the partial slab stencils200,300. For example, the dispensing heads462are each configured with a shutter or valve apparatus (not shown) that is controllable to regulate the flow of particulate mineral mix from the dispensing head462to the slab mold130. The dispensing heads462are controllable dispense fillers into the slab molds130at a substantially repeatable rate. Additional details of this particular embodiment of the dispensing head462are described further in connection withFIGS. 5A-6B.

In the illustrated example, two mineral aggregate distributors460a,406band two partial slab stencils200,300are used, although in other examples, the slab may be formed from between 2 and 20 different particulate mineral mixes, and more preferably between 3 and 8 different particulate mineral mixes (thereby providing a system that would include a corresponding number of distributors and partial slab stencils). In some examples, the number of mineral aggregate distributors and partial slab stencils can correspond equally to the number of differently pigmented particulate mineral mixes used to create the hardened slab product.

After the slab mold130has been sufficiently filled, the partial slab stencil300is disassembled from the slab mold130. The slab mold130(now a filled mold480) is moved on a cushion of air provided by an air table470, to an output conveyor120. As shown inFIG. 1, the successive complementary patterns of different particulate mineral mixes that were dispensed into the mold130are generally noticeable in the filled molds480and are arranged in the horizontal orientation on the output conveyer420. Some or all of these successive complementary patterns of different particulate mineral mixes can form the repeatably patterned veins of the hardened slab (e.g., the slab50inFIG. 1, the slab600inFIG. 6, or the like).

Optionally, the system400may include a secondary dispenser (not shown), which may be positioned so that each filled mold480passes under the secondary dispenser. The secondary dispenser can be configured to dispense a material that is used to define one more generally “widthwise” veins. Optionally, these widthwise veins may be thinner and spread further apart than the veins defined by the successive complementary patterns of different particulate mineral mixes. Also, these widthwise veins may be formed from a material having a different pigmentation than the particulate mineral mixes dispensed from the distributors460a,460b. In some embodiments, the secondary dispenser may be configured with a shutter or valve apparatus (not shown) that is controllable to regulate the flow of pigmented material, thereby providing a predetermined pattern of the widthwise veins that is repeatable for each of the filled molds480pass under the secondary dispenser. In some embodiments, the secondary dispenser can be configured to dispense a pigment powder material (e.g., not mixed with quartz material). In other embodiments, the secondary dispenser can be configured to dispense a particulate mineral mix (including a quartz material) having pigments that are different from the mixes dispensed from the distributors460a,460b. In some embodiments, the pigment powder material (or other material) dispensed from the secondary dispenser can be deposited along a major (exposed) side of the filled mold480so that at least a portion of the material penetrates at least slightly into the thickness of the mineral mix material previously poured into the mold480(thereby permitting the widthwise veins to remain viewable even after compaction and polishing of the slab). In such circumstances, the widthwise veins may not extend through the full thickness of the hardened slab (which is different from some or all of the veins defined by the successive complementary patterns of different particulate mineral mixes poured into the mold130by the distributors460a,460b).

Still referring toFIG. 4, the output conveyor420can be configured to transport each of the filled molds480to one or more sequent stations in the system400for forming the hardened slab. For example, each of the filled molds480can continue to a subsequent station in which a top mold attachment494is positioned over the filled mold480so as to encase the layers of particular mineral mixes between the mold130and a top cover mold piece (not shown inFIG. 4). From there, the filled mold480(now including the top cover mold piece continues to a subsequent station in which a vibro-compaction press495applies compaction pressure, vibration, and vacuum to the contents inside the filled mold480, thereby converting the particulate mixes into a rigid slab. After the vibro-compaction operation, the filled mold480(with the compacted and hardened slab therein) proceeds to a curing station496in which the material used to form the slab (including any resin binder material) are cured via a heating process, thereby further strengthening the slab inside the filled mold480. After the slab is fully cured (and cooled), the primary mold130and the top mold cover piece are removed from the hardened and cured slab at a mold removal station497. The primary mold130is then returned to the input conveyor410. Then, the hardened and cured slab is moved to a polisher station498, in which a major surface of the slab is polished to a smooth finish, thereby an appearance of the complex striations and veining patterns that emulate a quarried stone slab. In such circumstances, the polished major surface of each of the synthetic molded slabs provides an outer appearance that is generally repeatable for to the other slabs (from the other filled molds480inFIG. 4).

Now referring toFIG. 5A, the slab mold130is shown with the partial slab stencil200. The slab mold130is partly filled by drawing the distributor460alaterally across the partial slab stencil200, or by passing the partial slab stencil and the slab mold130laterally beneath the distributor460a. The distributor460aholds a first particulate mineral mix, which is controllably released though the dispensing head462into the slab mold130. The collection of occluded regions204block the dispensation of the mix into predetermined areas of the slab mold130, while the collection of apertures206allow the mix to fill predetermined areas of the slab mold130, shown as a collection of filled regions502.

Referring now toFIG. 5B, the slab mold130is shown with the partial slab stencil200removed after being partly filled according to the pattern provided by the partial slab stencil200. As a result, the slab mold130is partly filled with the first particulate mineral mix in the filled regions502, and is partly unfilled in a collection of unfilled areas504.

Now referring toFIG. 5C, the slab mold130is shown with the partial slab stencil300. The collection of occluded regions304substantially correspond to the collection of filled regions502(not visible in this view) and substantially prevent the second mix from being dispensed as a second layer upon the first mix already in the filled regions502. Conversely, the collection of apertures302substantially correspond to the collection of unfilled areas504left by the partial slab stencil200. For example the partial slab stencil300has a pattern that is the negative of the pattern of the partial slab stencil200, and the collective combination of the apertures202and302substantially correspond to the area (e.g., length L and width W) of the slab mold130.

The slab mold130is partly filled by drawing the distributor460blaterally across the partial slab stencil300, or by passing the partial slab stencil and the slab mold130laterally beneath the distributor460b. The distributor460bholds a second particulate mineral mix, which is controllably released though the dispensing head462into the slab mold130. The collection of occluded regions304block the dispensation of the mix into predetermined areas of the slab mold130, while the collection of apertures306allow the mix to fill the unfilled areas504of the slab mold130, shown as a collection of filled regions506.

Referring now toFIG. 5D, the slab mold130is shown with the partial slab stencil300removed after being partly filled according to the pattern provided by the partial slab stencil300. As a result, the slab mold130is partly filled with the first particulate mineral mix in the filled regions502, and is partly filled with the second particulate mineral mix in the filled regions506.

In some embodiments, three or more partial slab stencils, distributors, and particulate mineral mixes can be used. For example, four partial slab stencils can be used in which each partial slab stencil has a predetermined pattern of apertures that do not overlap those of the other stencils, and collectively combine to substantially correspond to the area of the slab mold130. Four different particulate mineral mixes (e.g., with different aesthetic qualities) can be dispensed into the four collections of apertures to create a four-color composite slab with a pattern that can be substantially repeated for multiple slabs.

Referring now toFIG. 6, an example synthetic molded slab product600can be formed by the system ofFIG. 4using a combination of differently pigmented particulate mineral mixes that are distributed according to predefined patterns of the two (or more) complementary partial slab templates200and300into the mold130. In some embodiments, the synthetic molded slab product600can provide a veined appearance that emulates quarried stone slabs such as granite or marble, depending upon the predefined dispensation pattern of the different particular mixes. For example, the major surface612of the slab600can be polished and provide at least some veins602,606that extend partly or fully across a length and/or width of the hardened slab600. Not only can such differently pigmented veins (602and606, for example) extend across the slab product, but such veins can also extend through the thickness610of the slab600from the first major face612to the opposing major face614(thereby providing a natural vein appearance even when the slab is cut and edged to specific shapes in living or working spaces (e.g., along a countertop, table, floor, or the like). Optionally, at least the major surface612of the slab600may include a plurality of secondary veins (not shown) defined, for example, by a secondary dispenser. Some of these “secondary” veins can extend fully across a complete width of the hardened slab600. Because each slab600in the set of separately molded slabs (refer, for example, to the system inFIG. 4) can include the regions of different particulate mineral mixes dispensed into the mold130according to the predefined and repeatable dispensation patterns of the partial slab stencils, multiple slabs600in the set can have similarly positioned veins in the major surface and can provide substantially the same appearance to one another.

The synthetic molded slab600can be cut, milled, machined, or otherwise processed to various shapes and sized (e.g., to provide custom-fit countertop surfaces with optional holes for sinks, faucets, or other amenities). For example, a section630is cut away from the synthetic molded slab product600. With the veins602and606extending into the interior606and/or across the thickness610, cutting and/or processing of the synthetic molded slab product600shows the veins602and606in a manner that emulates the aesthetics of cut quarried stone slabs.

FIG. 7is a flow diagram of an example process700for forming a synthetic molded slab product (such as slab50or600described above). In some implementations, the system400ofFIG. 4can be used to perform the process700. The process700may include the operation702of positioning a positive partial slab stencil in a slab mold. In such an operation, a partial slab stencil, such as the partial slab stencil200may be temporarily assembled to the slab mold130. The process700may also include the operation704of dispensing a first particulate mineral mix through the positive stencil into the slab mold. For example, as previously described, a first pigmented mix comprising predominantly a quartz material (e.g., a mix including the particulate quartz material, one or more pigments, and one or more resin binders) can be fed into the slab mold130using the distributor460a(FIG. 4). Next, the process700may include the operation706of removing the positive partial slab stencil, and may include the operation708of positioning a negative partial slab stencil in a slab mold. In such operations, the partial slab stencil200may be removed, and the partial slab stencil300may be temporarily assembled to the slab mold130.

The process700may also include the operation710of dispensing a second particulate mineral mix through the negative stencil into the slab mold. For example, as previously described, a second pigmented mix comprising predominantly a quartz material (e.g., a mix including the particulate quartz material, one or more pigments, and one or more resin binders) can be fed into the slab mold130using the distributor460b(FIG. 4). Next, the process700may include the operation712of removing the positive partial slab stencil. For example, the partial slab stencil300can be removed from the slab mold130.

The process700may further include the operation714of contemporaneously vibrating and compacting the particulate mineral mixes arranged in the mold while the mold is in the horizontal orientation. In such circumstances, the operation714may provide a compacted slab of composite stone material. Also, in some embodiments, the process700may further include the operation716of curing the compacted slab. The process700may also include the operation718of polishing a major surface of the slab to provide a veined appearance on the polished surface of the slab, including but not limited to the examples described above.