Patent Application
20240082978
This disclosure relates generally to apparatus, methods, and systems for finishing unfinished and/or partially finished plaster layers of block products.
Building structures such as walls are often built by organizing several individual masonry units into the structure. The masonry units may be pieces of cut stone, such as marble, granite, travertine, sandstone, or limestone. More frequently, the masonry units are some form of brick. Bricks are typically laid together in an alternating pattern of offset courses and joined together using mortar. The relatively smaller bricks often seen in residential applications are typically made of clay combined with sand or other type of aggregate. These bricks are usually fired to provide suitable strength.
Concrete is also utilized to form masonry units. Masonry units formed from concrete are often referred to as cinder blocks, breeze blocks, hollow blocks, construction blocks, clinker blocks, and Besser blocks. The terms “concrete blocks” and “concrete masonry unit” (CMU) are often used to generally refer to all such varieties. Concrete blocks are made from cast concrete, which typically includes Portland cement, water, and a suitable aggregate material. The concrete sets up and develops strength by hydration of the Portland cement. Lower cost concrete blocks often use industrial wastes such as low-quality fly ash or bottom ash for at least part of the aggregate. This is why such blocks are commonly referred to as “cinder blocks” in the U.S.
Concrete blocks are a useful, low-cost building material that are particularly useful for constructing walls or other weight bearing structures. However, concrete blocks are generally regarded as ugly, or too “industrial” for residential or business environments. While utilitarian, the concrete blocks typically do not create an esthetically pleasing structure, limiting their use to industrial or non-forward-facing environments. To expand their use, some concrete blocks may be coated with a plaster composition or other coating. This coating may be designed to create a more esthetically pleasing look to the concrete block.
Insulating concrete forms (ICFs) are another type of structural unit that is an energy and cost-efficient alternative to cinderblocks and concrete walls. Generally, ICFs comprise a rigid insulating layer forming exterior and/or interior wall products. The forms can comprise modular interlocking units that can be stacked, reinforced, and backfilled with concrete to form structural walls or floors of a building. Once locked in place, the interior space between inner and outer walls of the ICFs can be filled with concrete. Reinforcing steel bars (“rebar”) can be placed inside the ICFs before concrete is poured to give the concrete increased tensile and flexural strength.
However, ICFs, similar to concrete and cinderblocks, lack esthetic appeal and incur additional costs in labor and materials in order to apply esthetic coverings. Many preferred coverings may include high-quality stone or brick, which can be costly and labor-intensive to install. To expand their use, some ICFs may be coated with a plaster composition or other coating. This coating may be designed to create a more esthetically pleasing look to the ICF.
Application of coatings to a product introduces a new set of undesired variables. For example, the coating may not be applied uniformly to each concrete block, ICF, or other product, introducing undesirable variance in the look from one block to the next. Additionally, the coating may not be suitable for a broad range of environmental conditions (e.g., hot and sunny versus cold and humid). Further, the coatings may be applied in a sloppy and unpolished manner, meaning the resulting concrete block lacks the desired degree of esthetics.
Disclosed are methods and systems for finishing unfinished or partially finished block products that require further finishing. More particularly, the disclosed apparatus, methods, and systems can be used for finishing unfinished or partially finished plaster coatings or layers applied to one or more surfaces of block substrates. In some embodiments, a system for finishing plaster layers of block products includes one or more trimming stations, a coarse grinding station, a fine grinding station, a polishing station, an optional cleaning station, and an optional spraying station.
Example block products may include concrete block substrates, such as standard CMUs as core component or block substrate, that are coated with a plaster or other cementitious coating layer. Block substrates can be made of fired clay, ceramic, unfired clay, or other materials. Block substrates may alternatively include insulated concrete forms (ICFs) or other lightweight blocks that are coated with a plaster or other cementitious coating layer. The block products include at least one surface having or treated with a coating, where the coating is a plaster or other cementitious composition. The terms “plaster”, “plaster material”, “plaster composition”, “plaster layer”, and “plaster coating” shall refer to any plaster or other cementitious composition applied to the surface of a block substrate.
Plaster compositions used to coat a block substrate typically include a cementitious binder component, water, aggregate, and one or more admixtures. The cementitious binder may include Portland cement, such as white cement or grey cement, alone or in combination with one or more supplementary cementitious materials (SCMs), such as fly ash, metakaolin, ground pumice, natural pozzolan, ground metallurgical slag, or silica fume. The aggregate may include one or more sizes of sand, such as one or more limestone sands or powders of different size range. In some embodiments, the plaster composition may include an internal sealer. In some embodiments, the plaster composition may include an adhesive that promotes bonding of the plaster composition to the block product.
An initially fresh plaster composition formed by mixing cement, water, aggregates, and admixture(s) is typically a flowable composition that can be applied to a block surface, which thereafter hardens and develops strength over time through hydration of the Portland cement. SCMs can react with excess lime (CaO) released from Portland cement during hydration via the pozzolanic reaction. This yields initial block products with one or more initially unfinished plaster layers.
The initial or intermediate block products can have bulging, drooping, or excess plaster layer(s) on one or more sides of the block substrates. This is undesirable, as block products may appear sloppy and unfinished, and the unevenness may inhibit proper placement of block products in desired patterns. Thus, the present invention provides apparatus, methods, and systems for finishing and improving the aesthetic look and functionality of finished block products. A method of finishing initial block products includes providing initial or intermediate block products having one or more hardened plaster layers and passing the initial or intermediate block products through a series of finishing zones or stations that perform various finishing processes or steps to yield finished block products.
In a trimming zone or station, excess plaster composition, typically in a hardened condition, is trimmed away from one or more sides of the initial block products in one or more steps, such as by cutting and/or sanding. In some embodiments, this involves removing a portion of the plaster coating layer that has bulged, drooped, or sloughed down the side(s) (e.g., long sides and/or short sides) of the initial block products. The trimming zone or station may include a first subzone that includes trimming apparatus, such as one or more circular saw blades or grinders, configured to trim excess plaster from first essentially parallel sides (e.g., lengthwise or short sides) of block products and a second subzone that includes trimming apparatus, such as one or more circular saw blades, configured to trim excess plaster from second essentially parallel ends (e.g., widthwise or long sides) of block products.
In a coarse grinding zone or station, one or more surfaces (e.g., top and/or bottom surfaces) of the trimmed plaster layer(s) is/are coarsely ground to level out and reduce the thickness of the plaster layer(s). This creates a more uniform plaster surface that is preferably essentially planar. The second finishing zone can utilize a coarse grinding cylinder or roller.
In a fine grinding zone or station, the one or more coarsely ground plaster layers are finely ground to remove or reduce surface coarseness and defects that may remain after the coarse grinding process. The fine grinding process may only minimally reduce the thickness of the coarsely ground plaster layer(s), if at all, and mainly smooth out protrusions and concavities that remain after the coarse grinding process. The third finishing zone can utilize a fine grinding cylinder or roller.
In a polishing zone or station, the one or more finely ground plaster layers are polished to further remove surface defects that may remain after the fine grinding process and create a smooth, polished, and esthetically pleasing surface. The polishing process typically does not appreciably reduce the thickness of the finely ground plaster layer(s) except for minor discontinuities in the surface finish that may remain after the fine grinding process. The fourth finishing or polishing zone can utilize a polishing cylinder or roller.
In one or more optional finishing zones or stations, the one or more polished plaster layers can be cleaned and/or provided with a surface treatment. In one optional finishing zone, the one or more polished plaster layers are cleaned with pressurized air and/or water to remove dust, debris, or other contaminants from the polished surface(s). In another optional finishing zone, an optional surface treatment is applied to the polished and cleaned plaster layer surface(s), such as a curing agent and/or sealer.
The grinding and polishing processes can enhance the esthetic appeal of finished block products. For example, they can beneficially abrade coarse sandy aggregates in the hardened plaster layer to form and/or expose the crystal facets that can resemble those of natural cut stone. The optional sealer may include a polymer or other sealant that seals, waterproofs, and/or protects the plaster layer(s). The optional sealer may provide a desired look, such as a glossy or matte finish and/or a wet or dry look. A pigment may optionally be included in the optional sealer or other optional surface treatment to alter or enhance the color of the finished plater layer(s).
Also disclosed herein are systems for finishing initial or intermediate block products having one or more plaster coating layers that require further finishing. In one embodiment, a system for finishing block products includes a conveyance system with a conveyor configured to convey one or more initial or intermediate block products, and a trimming zone configured to receive the initial or intermediate block products and remove excess plaster composition from the sides (e.g., long sides and short ends) of the initial or intermediate block products. The system also includes other finishing zones configured to progressively sand, abrade, and polish the plaster layer on one or more surfaces of the initial or intermediate block products. Optionally, the system may also include a cleaning zone, where dust, debris, and other contaminants are removed from finished or semi-finished block products. The system may optionally include a surface treatment zone, in which a surface treatment may be applied to the plaster layer(s) on the surface(s) finished or semi-finished of block products.
Beneficially, the disclosed systems and methods produce finished block products that have the appearance of cut stone. Such appearance can add to and/or improve the aesthetic look and finish of structures built from the finished block products. The block products can be utilized with less expense and with greater design freedom as compared to actual cut stone. For example, finished block products according to the disclosure may be lighter in weight and more esthetically consistent than actual cut stone. A greater number of possible looks are possible compared to the limited number of types of stone products available in a region. As some embodiments apply a sealer to the finished plaster layer(s), the block products produced herein can be more resilient and have better resistance to weathering conditions, such as rain, snow, wind, and heat (e.g., sun exposure).
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.
Various objects, features, characteristics, and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings and the appended claims, all of which form a part of this specification. In the Drawings, like reference numerals may be utilized to designate corresponding or similar parts in the various Figures, and the various elements depicted are not necessarily drawn to scale, wherein:
I. Block Products and Substrates
The block products described herein comprise block substrates that have been modified or enhanced by applying a plaster composition to at least one surface of the block substrates. In some embodiments, the block substrate can be a standard CMU, fired clay block, ceramic block, or unfired clay block. In other embodiments, the block substrate may alternatively be an insulated concrete form (ICF), structural tile, gypsum block, or other construction unit capable of being arranged with multiple units to form a building structure. For simplicity, the following description will use the term “block substrate” to refer generally to the foregoing types of base substrates, as well as other block substrates known in the art, that can be coated with a plaster composition and finished to form a “block product”.
Particularly preferred embodiments utilize CMUs as block substrates, though it will be understood that the embodiments described herein are not limited solely to CMUs. In the United States, CMUs are commonly sized at about 16 in×8 in×8 in, though they may be varied in one or more dimensions by ±4 to 10 inches. For example, it may be desirable to use a CMU that is 24 in×8 in×8 in.
In some embodiments, the block substrates can be lightweight ICFs or other lightweight block products that can be modified by applying a plaster composition to at least one surface of the lightweight block product. The lightweight block substrate comprises a lightweight material, such as lightweight foam concrete, lightweight foam ceramic, expanded polystyrene (EPS), extruded polystyrene foam (XPS), polyurethane foam, cement-bonded wood fiber, cement-bonded polystyrene beads, cellular concrete, or similar materials having a density of less than 1680 kg/m3.
In some embodiments, the lightweight block substrate comprises a lightweight material having a density less than about 1500 kg/m3, or less than about 1250 kg/m3, or less than about 1000 kg/m3, or less than about 750 kg/m3, or less than about 500 kg/m3, or less than about 300 kg/m3, or less than about 200 kg/m3, or less than about 150 kg/m3, or less than about 100 kg/m3, or less than about 80 kg/m3, or less than about 60 kg/m3.
The plaster composition can be formulated to provide a desired decorative appearance to one or more surfaces of the block substrate. The plaster composition may, for example, provide the appearance of natural stone, such as cut stone. The block product can therefore be utilized in architectural and/or decorative applications with less expense and with greater design freedom as compared to actual stone.
The cuboid shape (e.g., a three-dimensional rectangular prism) of the block product 100 is typical of most blocks, though other embodiments may be shaped differently so long as they may be arranged with other units to form a building structure. For example, other embodiments of block substrate and products may have a cube shape, a trapezoidal prism shape, a panel/tile shape, a shape with a polygonal cross-section, or a shape with one or more curved surfaces. Additionally, and/or alternatively, some embodiments may include corners and/or edges that are rounded, beveled, chamfered, or the like.
Each ICF panel 206, 208 includes opposing short sides 210, 212, opposing long edges 214, 216, and opposing short edges 218, 220. The block product 200 includes modular and interlocking features that enable stacking of the block products 200 in a number of configurations. U.S. Patent Publication No. 2021/0396005, which is incorporated herein by reference, discloses examples and descriptions of various stacking features and configurations utilizing block products 200.
In some embodiments, only a single surface of the block product 100, 200 includes a plaster layer 104, 204 forming decorative surfaces 104, 206. Once multiple block products 100, 200 have been arranged to form a building structure, the decorative surfaces 104, 206 are usually the only surfaces that are visible. The back sides and opposing short sides are typically hidden. However, in other embodiments, more than one surface may be treated according to the needs of a particular application. For example, corner and end pieces may have two or more exposed side surfaces following formation of the building structure. Such exposed side surfaces can also have a plaster layer applied thereto. In some cases, rear surfaces may remain visible after construction, such as where the block products are used to form a partition wall that remains visible on either side of the wall following construction. In such cases, the front and back surfaces may be treated to have or include a plaster layer.
The plaster composition used to form plaster layers 104, 204 can be formulated to provide an aesthetic appearance resembling that of natural stone, such as cut stone, once the block products have gone through the disclosed finishing process(es). The block substrates and methods used to finish the plaster layers applied thereto to form finished block products provide a less expensive alternative to natural stone. Further, using natural stone may involve difficulties in finding a proper and consistent supply of stone. In other words, the use of natural stone may require an extensive search for a proper supply that meets size and/or composition and/or esthetic requirements. In contrast, the block products described herein are capable of being manufactured according to a wide variety of specifications to meet particular project requirements.
In some embodiments, block products may also be provided at a weight that is significantly less than natural stone. Block products may therefore provide the aesthetic benefits of natural stone while reducing limitations associated with cost, weight, and/or supply of natural stone. In addition, interior cavities in block products facilitate the use of rebar, pipes, wiring, interior bonding concrete, mortar, and the like.
II. Plaster Compositions
The plaster compositions applied to block substrates may be formulated to include: 1) a cementitious binder, 2) water, 3) an aggregate, preferably including at least two types and/or gradations of aggregate (e.g., limestone sand and/or silica sand), and 4) one or more admixtures, such as a water reducer, superplasticizer, adhesive, and/or internal sealer. These are mixed to form a fresh plaster composition in a plastic or flowable state suitable for application to the block substrate surface.
The fresh plaster composition may be applied to block substrates and then caused or allowed to harden or cure to form a decorative plaster coating, which can then be finished by trimming, grinding, and polishing to yield finished block products with one or more plaster layers, such as plaster layers 104, 204 illustrated in
The cementitious binder preferably comprises white Portland cement. Although some embodiments may optionally include ordinary (grey) Portland cement and/or supplementary cementitious materials (SCMs), the cementitious binder component preferably includes at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or 100%, of white Portland cement. One or more SCMs may optionally be included in the cementitious binder, examples of which include fly ash, ground granulated blast furnace slag (GGBFS), metakaolin, silica fume, pumice, volcanic ash, ground glass, natural pozzolan, and ground limestone. The cementitious binder component may constitute about 15% to 45%, more preferably about 20% to 40% (e.g., about 25% to 35%) of the dry weight of the plaster composition (excluding water). Pigments may optionally be included to provide a desired color of the plaster composition.
The aggregate component may constitute about 55% to 85%, more preferably about 60% to 80% (e.g., about 65% to 75%) of the dry weight of the plaster composition (excluding water). The aggregate component preferably includes at least two gradations and/or types of aggregate material. Beneficial results closely resembling the appearance of natural cut stone can be obtained by including both fine sand and coarse sand as aggregate in the plaster composition.
In some embodiments, the aggregate may include two or more gradations of limestone sand, two or more gradations of silica sand, or a combination thereof. Limestone sand is softer than silica sand and may be easier to expose and finish by grinding and polishing. Silica sand may provide a more defined crystal structure and greater strength. An example aggregate may include a fine limestone and/or silica sand portion, and a coarse limestone and/or silica sand portion.
As used herein, the “fine” or “fine sand” portion of the aggregate is a sand having a D90 of about 0.425 mm or less (i.e., where at least 90% of the particles pass through a 40 mesh sieve), or about 0.300 mm or less (i.e., where at least 90% of the particles pass through a 50 mesh sieve), or even about 0.212 mm or less (i.e., where at least 90% of the particles pass through a 70 mesh sieve). For example, the D90 of the fine sand portion may be in a range of about 0.075 mm to about 0.425 mm, or about 0.105 mm to about 0.300 mm, or about 0.150 mm to about 0.212 mm. The fine sand portion may also have a D50 that is about 0.075 mm or less (i.e., where at least 50% of the particles pass through a 200-mesh sieve). The fine sand can be considered to be a filler rather than an SCM forming part of the cementitious binder.
As used herein, the “coarse” or “coarse sand” portion of the aggregate is a sand or other particle having a D90 greater than about 0.425 mm (i.e., less than 90% of the particles pass through a 40-mesh sieve), or greater than about 0.60 mm (i.e., less than 90% of the particles pass through a 30-mesh sieve). For example, the D90 of the coarse sand portion may be in a range of about 0.425 mm to about 2.80 mm, or about 0.60 mm to about 1.70 mm. The coarse sand portion may have a D50 in a range of about 0.212 mm to about 0.60 mm, or about 0.300 mm to about 0.425 mm. The coarse sand portion may have a D10 in a range of about 0.075 mm to about 0.212 mm, or about 0.105 mm to about 0.150 mm.
Plaster compositions having aggregates with fine and coarse sand portions as defined herein have been found to be effective in providing the appearance of natural stone, such as cut stone, e.g., when ground and polished to expose crystal facets. The fine sand portion enables effective application of the plaster composition to the treated surface of a block substrate and facilitates even coverage of the treated surface. The coarse sand portion can provide visible crystal facets that can be exposed by finishing (e.g., sanding and/or polishing) of the plaster surface. These visible crystals can resemble crystals facets within natural cut stone.
Adjusting the ratio of the fine sand portion to the coarse sand portion can enhance the resemblance to natural stone. For example, the appearance of the finished plaster layer was found to resemble natural cut stone when the ratio of the fine sand portion to the coarse sand portion is in a range about 1:9 to about 5:5, more preferably about 2:8 to about 4:6. For example fine sand may constitute about 10% to about 50%, or about 20% to about 45%, or about 25% to about 40% of the weight of the aggregate component of the plaster composition, and the remainder may comprise coarse sand. These ratios were found to beneficially balance the different features of the fine and coarse aggregate portions to result in a plaster composition having good workability, finishability, and resemblance to natural stone, such as cut stone.
In some embodiments, the plaster composition may include an internal sealer. The plaster composition may include an internal sealer in an amount ranging from about 0.05% to about 0.1%, or about 0.06% to about 0.09%, or about 0.07% to about 0.08% of the weight of the plaster composition (excluding water) or within a range defined by any two of the foregoing values. In some embodiments, the plaster composition comprises approximately 0.075% by weight of the internal sealer (excluding water). Beneficially, the internal sealer enables the plaster composition to withstand weathering conditions. The internal sealer also provides the plaster composition with a level of waterproofing. An example internal sealer is KreteControl 230, which provides water repellence and efflorescence control and minimizes water penetration and absorption, improves service life, improves aesthetic appearance, and promotes and maintains brighter colors.
In some embodiments, the plaster composition may include an adhesive component, such as in an amount ranging from about 2% to about 10%, or about 3% to about 9%, or about 4% to about 8%, by weight of the plaster composition (excluding water). In a preferred embodiment, the adhesive component is a latex or latex-based adhesive (e.g., polyvinyl acetate, polyvinyl alcohol, and the like), though other embodiments may additionally or alternatively include other adhesives, such as those based on styrene, acrylonitrile, natural rubber, neoprene, polyurethane, and combinations thereof.
Including an adhesive component can enhance the internal integrity of the plaster layer as it hardens or cures on the treated substrate surface. Additionally, the adhesive component aids in maintaining good contact and bond strength between the plaster composition and the block substrate surface to ensure effective coverage and bonding. The adhesive can also minimize sloughing, buckling, or other undesirable flows from occurring during application of the plaster composition, which reduces such flaws or artifacts in the finished, cured product.
One or more additional components may be included in the plaster composition to aid in application and/or to provide desired properties to the finished, cured product. For example, one or more dyes or colorants (e.g., white, cream, tan, brown, orange, red, etc.) may be included to provide a desired color scheme to the plaster and further aid in reproducing the appearance of natural stone. A set retarder that slows down cement hydration can be included to extend working time of the plaster composition. In addition, and/or alternatively, a set accelerator may be included to speed up hardening for subsequent handling. Water reducers and plasticizers (i.e., that reduce the amount of water required to yield a plaster composition having desired flow or plastic behavior), rheology modifiers, and/or other admixtures known in the art can be included.
An example of a currently preferred method and system for applying plaster compositions to block substrates to form initial or unfinished block products is disclosed in U.S. application Ser. No. 18/144,591, filed May 8, 2023, and entitled “System And Method For Manufacturing Architectural Blocks With Stone-Like Appearance”, which is incorporated by reference in its entirety.
III. Apparatus, Methods and Systems for Finishing Block Products
Disclosed are apparatus, methods, and systems for finishing intermediate block products having one or more hardened but initially unfinished plaster layer(s). For example, the disclosed apparatus, methods, and systems may be used for finishing one or more layers of a plaster coating composition applied to block substrates. The disclosed apparatus, methods, and systems may also be used to finish other cementitious products and compositions applied to block substrates. Block substrates may include, for example, concrete blocks (e.g., standard CMUs) or insulated concrete forms (ICF)s. Block substrates made of fired clay, ceramic, unfired clay, or other materials can also be used. In one embodiment, a block product includes at least one surface having or treated with a plaster composition to provide an esthetic plaster coating layer.
A system for finishing initial or intermediate block products having a plaster layer on a surface thereof includes a trimming zone or station for trimming or removing a portion of hardened or semi-hardened plaster composition that has bulged, drooped, or ran down the side(s) (e.g., long sides and/or short sides) of the intermediate block products. The system also includes a series of finishing grinding and polishing zones including grinding and polishing machines configured to progressively grind, smooth, and polish the plaster layer(s) on the surface(s) of block substrates. The system may include a conveyor to move the initial or intermediate block products and pass them through the various finishing zones or stations. The system may optionally include a cleaning zone or station configured to remove dust, debris, and other contaminants from finished or semi-finished block products. The system may optionally include a surface treatment zone or station, where a surface treatment may be applied to finished or semi-finished block products.
A method of finishing initial or intermediate block products includes the steps of providing a plurality of initial or intermediate block products and passing the plurality of block products through a series of finishing zones or stations. The finishing process beneficially removes (e.g., trims) excess plaster material and abrades the plaster layer to yield a block product with a finished look. In some cases, grinding and polishing the plaster layer(s) forms and/or exposes crystal facets of sand particles that can resemble those of natural stone, such as cut stone.
In a trimming zone or station, excess plaster composition, typically in hardened or semi-hardened condition, is trimmed away from one or more sides of the initial block products in one or more steps, such as by cutting and/or grinding. In some embodiments, this involves removing a portion of the plaster coating composition that has bulged, drooped, or ran down the side(s) (e.g., long sides and/or short sides) of the initial block products. The presence of bulging, drooping, or sloughed off plaster composition on the sides of the block product is undesirable as it makes the block product look sloppy and unfinished. It may also diminish performance and use by creating differently sized blocks that are difficult to place in a desired configuration. For example, the presence of bulging, drooping, or sloughing of excess plaster composition on the sides of the block products may prevent the block products from properly aligning or stacking with each other. Improper alignment or stacking may result in a low esthetic and/or unstable building structure. The trimming zone or station may include a first subzone that includes trimming apparatus, such as one or more circular saw blades or grinders, configured to trim excess plaster from first essentially parallel sides (e.g., lengthwise or short sides) and a second subzone that includes trimming apparatus, such as one or more circular saw blades or grinders, configured to trim excess plaster from second essentially parallel ends (e.g., widthwise or long sides).
In a coarse grinding zone or station, one or more surfaces (e.g., top and/or bottom surfaces) of the trimmed block products are coarsely ground to level out and reduce the thickness of the plaster layer(s). This creates a more uniform plaster surface that is preferably essentially planar. The coarse grinding zone or station can utilize a coarse grinding cylinder or wheel.
In a fine grinding zone or station, the one or more coarsely ground plaster layers (e.g., top and/or bottom) are finely ground to remove or reduce surface coarseness and defects that may remain after coarse grinding. The fine grinding process may only minimally reduce the thickness of the coarsely ground plaster layer(s), if at all, and mainly smooth out protrusions and concavities that remain after coarse grinding. The fine grinding zone or station can utilize a fine grinding cylinder or wheel.
In a polishing zone or station, the one or more finely ground plaster layers (e.g., top and/or bottom surfaces) of the block product are polished to further remove surface defects that may remain after fine grinding and create a smooth, polished, and esthetically pleasing surface. The polishing process typically does not appreciably reduce the thickness of the finely ground plaster layer(s) except for minor discontinuities in the surface finish that may remain after fine grinding. The fourth finishing or polishing zone can utilize a polishing cylinder or wheel.
As the block products move through each grinding and/or polishing zone or station, the grit size advantageously gets progressively finer. Such grinding and polishing processes sand, abrade, buff, and polish the plaster layer, exposing crystal or other facets of sand particles in the plaster composition, which can give the block products the appearance of natural stone. As the plaster layer is processed by the grinding and polishing apparatus, the thickness of the plaster layer is reduced. For example, the plaster layer can have an initial thickness ranging from about 3/16 to about ⅝ inch, or about ¼ to about ½ inch. After moving through and being processed by the grinding and polishing apparatus, the final thickness of the plaster layer(s) may range from about 1/32 to about 3/16 inch, or about 1/16 to about ⅛ inch.
In one or more optional finishing zones or stations, the one or more ground and polished plaster layers (e.g., top and/or bottom surfaces) of the block products can be cleaned and/or provided with a surface treatment. In one optional finishing zone, the one or more polished plaster layers are cleaned with pressurized air and/or water spray to remove dust, debris, or other contaminants from the ground and polished plaster layer(s). In another optional finishing zone, one or more optional surface treatments, such as a curing agent and/or sealer, can be applied to the polished and cleaned plaster layer(s).
The grinding and polishing processes can enhance the esthetic appeal of finished block products. For example, they can beneficially abrade coarse sandy aggregates in the hardened plaster layer(s) to form and/or expose the crystal facets that can resemble those of natural cut stone. The optional sealer may include a polymer or other sealant that seals, waterproofs, and/or protects the plaster layer(s). The optional sealer may provide a desired look, such as a glossy or matte finish and/or a wet or dry look. A pigment may optionally be included in the optional sealer or other optional surface treatment to alter or enhance the color of the finished plater layer(s).
As illustrated in
The initial or intermediate block products 200 have an amount of plaster composition 224 applied to a surface thereof. This may be the plaster layer 104 illustrated in
The plaster composition 224 may be applied to a surface of block substrates and allowed to harden or cure, after which the initial or intermediate block products 200 are moved toward the series of finishing zones or stations. As illustrated in
Following grinding and polishing of the plaster layer 224, the finished or semi-finished block products 200 may be moved through an optional cleaning zone including a cleaner 232. The cleaner 232 may be configured to discharge compressed air, water, and/or other suitable fluids to clean the surface of the polished plaster layer 224. Other embodiments may additionally or alternatively utilize one or more brushes or vacuum devices, for example, to remove residual dust or other debris from the treated surface.
The finished or semi-finished block products 200 may then be conveyed to another optional finishing zone including a sprayer 234, which may be configured to apply a surface treatment to the plaster layer 224. The sprayer 234 may utilize a sprayer and/or roller brush, for example, to apply a surface treatment to the plaster layer 224. The surface treatment may include one or more of a sealer or densifier, a glossy finish (e.g., an epoxy or resin), a matte finish, a pigment, and/or other suitable finishes configured to impart a desired esthetic characteristic to the block product 200.
As illustrated in
The initial or intermediate block products 300 have an amount of plaster composition 324 applied to a surface thereof. This may be the plaster layer 204 illustrated in
The plaster composition 324 may be applied to a surface of the block products 300 and allowed to harden or cure, after which the initial block products 300 are moved toward the series of finishing zones or stations. As illustrated in
Following grinding and polishing of the plaster layer 324, the block products 300 may be moved through an optional cleaning zone including a cleaner 332. The cleaner 332 may be configured to discharge compressed air, water, and/or other suitable fluids to clean the surface of the finished and polished plaster layer 324. Other embodiments may additionally or alternatively utilize one or more brushes or vacuum devices, for example, to remove residual dust/debris from the treated surface.
The block product 300 may then be conveyed to another optional finishing station including a sprayer 334, which may be configured to apply a surface treatment to the plaster layer 324. The sprayer 334 may utilize a sprayer and/or roller brush, for example, to apply the surface treatment to the treated surface of the plaster layer 324. The surface treatment may include one or more of a polymer or sealant, a glossy finish (e.g., an epoxy or resin), a matte finish, a pigment, and/or other suitable finishes configured to impart a desired esthetic characteristic to the block product 300.
a. Trimming Excess Plaster Material from the Sides
In some embodiments, the first and second trimming zones or stations 700, 800 each include housings 710 and 810, at least one pair of opposing cutting blades 712 and 812, and a vent (not shown) attached to a top of the housings 710, 810. In some embodiments, the pair of opposing cutting blades 712, 812 include a pair of diamond blades. The diamond blades may have a diameter of approximately 5 to 7 inches, such as a 6-inch diameter. In some embodiments, the blades can be driven by a motor (not shown) to rotate at approximately 10,000 to 12,000 RPM, such as 11,000 RPM, during the trimming process. Alternatively, grinding apparatus (not shown) can be used to trim the sides of the intermediate block products 702. The housings 710, 810 can be approximately box-shaped and include/define a channel that is sized and shaped to receive and accommodate an unfinished/intermediate block product 702, such as block products 200 or 300. In some embodiments, the housing 710, 810 is disposed over and accommodates a conveyor belt 714, 814. The conveyor belt 714, 814 moves the initial block product 702 through the channel and, thus, through the housing 710, 810.
In some embodiments, the width, height, and length of the channel may be slightly greater than the width, height, and length of the block product. For example, the block product may have a width and a height of approximately 8 inches and a length of approximately 16 inches. The channel may accordingly have a width and height slightly greater than 8 inches, and a length slightly greater than 16 inches. The width/height of the channel may be slightly greater than the width/height of the block product to permit the block product to move through the channel without scraping the channel sides and/or getting stuck. For example, the channel may have a width/height of approximately 8.1 to 9 inches to properly accommodate the block product.
The first trimming zone or subzone of
The second trimming zone or subzone of
The channel is also sized such that, as the unfinished block products are moved through the channel, the opposing blades 712, 812 contact the opposing sides (e.g., long or short) or edges of the block products 702. As shown in
The cutting blades 712 are oriented such that a plane or face of each blade 712 is approximately parallel to a face or plane of each of the short sides of the block product 702. The blades 712 cut off or trim portions of the plaster layers 704 that have drooped, bulged, or ran down the sides of the block product. By trimming the portions of plaster layers 704 that have drooped down sides of block products 702, the plaster layer(s) 704 become approximately flush and continuous with the sides of the block substrates 706. That is, the plaster layer 704 leaves no ridges or bumps where the edges of the sides of the block substrate 706 meet the surface having the plaster layer 704. Alternatively, the cutting blades 712 can be spaced-apart by an inner distance to yield a trimmed plaster layer 704 that is slightly longer than the block substrate 706 (e.g., to avoid cutting the sides of the block substrate 706 and/or damaging the lengthwise ends of the trimmed plaster layer 704).
As shown in
The opposing blades 812 are oriented such that a plane or face of each blade 812 is approximately parallel to a face or plane of each of the long sides of the block substrate 706. The blades 812 cut off portions of the plaster layers 704 that have drooped, bulged, or ran down the sides of the block substrates 706. By cutting off excess portions of the plaster layers 704, they become flush and continuous with the sides of the block substrates 706. That is, the plaster layer 704 leaves no ridges where the top edges of the sides of the block substrate 706 meet the surface having the plaster layer 704. Alternatively, the cutting blades 812 can be spaced-apart by an inner distance to yield a trimmed plaster layer 704 that is slightly wider than the block substrate 706 (e.g., to avoid cutting the sides of the block substrate 706 and/or damaging the widthwise ends of the trimmed plaster layer 704).
b. Coarse Grinding of the Plaster Layer
The roller 904 may be a coarse cylinder grinder or other appropriate grinder. The roller 904 of the coarse grinding machine 900 can have a grit size ranging from about 20-grit to about 35-grit, such as about 25-grit or about 30-grit. In some embodiments, the roller 904 is a 30-grit roller with a size of approximately 5½×18½ inches in diameter and length, respectively. The coarse grit size enables the plaster layer 704 to be ground or sanded down to remove a thickness of the plaster layer 704. For example, a thickness of approximately ⅛ to ⅜ inch of the plaster layer 704 may be removed. For example, the plaster layer 704 may initially be applied at a thickness of about ¼ to about ½ inch, and the plaster layer 704 may be ground down to a thickness of about 1/16 inch to about ⅛ inch. This creates a more uniform surface that, in some embodiments, is essentially planar.
c. Fine Grinding of the Plaster Layer
The roller 1004 may be a medium or fine cylinder grinder or other appropriate grinder. The roller 1004 of the fine grinding machine 1000 can have a grit size ranging from about 70-grit to about 85-grit, such as about 75-grit or about 80-grit. In some embodiments, the roller 1004 is an 80-grit roller with a size of approximately 5½×18½ inches in diameter and length, respectively. The fine grit size enables the plaster layer 704 of the block product 702 to be finely ground to remove or reduce surface coarseness and defects that may remain after and/or are caused by the coarse grinding process. The fine grinding process may only minimally reduce the thickness of the coarsely ground plaster layer 704 and mainly smooths out protrusions and concavities that result from the coarse grinding process.
d. Polishing of the Plaster Layer
The roller 1104 may be a polishing cylinder. The roller of the polishing machine 1100 can have a grit size ranging from about 110-grit to about 125-grit, such as about 115-grint or about 120-grit. In some embodiments, the roller 1104 is a 120-grit roller with a size of approximately 5½×18½ inches in diameter and length, respectively. The very fine grit size enables the plaster layer 704 of the block product 702 to be polished to further remove any surface defects that may remain after and/or caused by the fine grinding process and to create a smooth, polished, buffed, and esthetically pleasing surface. The polishing process typically does not appreciably reduce the thickness of the finely ground plaster layer 704 except for minor discontinuities in the surface finish that may remain after the fine grinding process.
e. Optional Finishing of Plaster Layers and Block Products
After the block products have passed through the series of trimming/grinding/polishing zones, the block products may be considered “finished” or semi-finished. That is, the plaster layer has been ground down, leveled, and polished, with exposed crystal facets or other esthetic characteristics. The block products may go through optional final steps of the disclosed finishing processes to (i) remove dust and other debris from the finished block product, and/or (ii) apply a surface treatment to the polished/sanded plaster layer.
The sprayers 232, 332 include a channel and a spray nozzle or mister. The spray nozzle or mister is configured to apply a surface treatment to the finished plaster layers 224, 324 of the block products 200, 300. The spray nozzle or mister 232, 332 may apply one or more layers of the surface treatment to the plaster layer 224, 324. The surface treatment may include one or more of a sealer or densifier to seal, waterproof, and/or protect the plaster layer 224, 324. Additionally, and/or alternatively, the surface treatment may provide a glossy or matte finish, and/or a pigment to provide color to the plaster layer 224, 324.
A fourth step 1540 includes coarsely grinding the plaster layer of the trimmed block products from steps 1520 and 1530 in a coarse grinding station. For example, a portion of the plaster layer may be removed and sanded down. A fifth step 1550 includes finely grinding the coarsely ground plaster layer of the block products from step 1540 in a fine grinding station. Finely grinding the plaster layer smooths out the plaster layer in a polishing station, removing imperfections, protrusions, and concavities from the plaster layer. A sixth step 1560 includes polishing the finely ground plaster layer to polish and buff the plaster layer, increasing the luster of crystal facets or other esthetic characteristics and yielding finished block products.
A seventh optional step 1570 includes passing the plurality of block products through a cleaning station and blowing compressed air and/or spraying water onto the plaster layer. Passing the block products through the cleaning station removes dust or other debris that may remain on the block products, including the plaster layer, as a result of subjecting the block products to the trimming, grinding, and polishing stations. The cleaner may include a blower configured to deliver compressed air, water and/or other appropriate fluids to remove dust and debris. An eight optional step 1580 includes spraying a sealer or other treatment onto the block products, including the plaster layer. The sprayer may include a spray nozzle or mister configured to apply the sealer or other surface treatment to the plaster layer of the block products.
While certain embodiments of the present disclosure have been described in detail, with reference to specific configurations, parameters, components, elements, etcetera, the descriptions are illustrative and are not to be construed as limiting the scope of the claimed invention.
Furthermore, it should be understood that for any given element of component of a described embodiment, any of the possible alternatives listed for that element or component may generally be used individually or in combination with one another, unless implicitly or explicitly stated otherwise.
In addition, unless otherwise indicated, numbers expressing quantities, constituents, distances, or other measurements used in the specification and claims are to be understood as optionally being modified by the term “about” or its synonyms. When the terms “about,” “approximately,” “substantially,” or the like are used in conjunction with a stated amount, value, or condition, it may be taken to mean an amount, value or condition that deviates by less than 20%, less than 10%, less than 5%, less than 1%, less than 0.1%, or less than 0.01% of the stated amount, value, or condition. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Any headings and subheadings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims.
It will also be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” do not exclude plural referents unless the context clearly dictates otherwise. Thus, for example, an embodiment referencing a singular referent (e.g., “widget”) may also include two or more such referents.
It will also be appreciated that embodiments described herein may also include properties and/or features (e.g., ingredients, components, members, elements, parts, and/or portions) described in one or more separate embodiments and are not necessarily limited strictly to the features expressly described for that particular embodiment. Accordingly, the various features of a given embodiment can be combined with and/or incorporated into other embodiments of the present disclosure. Thus, disclosure of certain features relative to a specific embodiment of the present disclosure should not be construed as limiting application or inclusion of said features to the specific embodiment. Rather, it will be appreciated that other embodiments can also include such features.
This Application claims the benefit of U.S. Provisional Application No. 63/405,230, filed Sep. 9, 2022, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63405230 | Sep 2022 | US |
