Patent Application
20060026919
The invention relates to imitation stone and to imitation stone siding for application to a building or other architectural structure. Further the invention relates to a system for manufacturing the imitation stone and the siding.
An imitation stone is manufactured from a material composition that is cast or molded. It is important that the imitation stone duplicate or imitate the aesthetic appearance of a wall laid up with natural stone. According to U.S. Pat. No. 5,634,307, a material composition for making imitation stone comprises a mixture of Portland cement and polymeric resins entrained with metallic particles or sand and pigments.
Other material compositions for making imitation stones are disclosed, by way of example, in U.S. Pat. Nos. 5,364,672 and 5,451,620. According to the patents, a matrix of thermoplastic resins and Portland cement are disclosed, to which fillers are added to simulate the aesthetic appearance of natural stone. For example, the patents disclose fillers in the form of aggregates of silica, sand, colored glass fragments and metal particles. The compositions are cast or molded into shapes that resemble quarried natural stone. Prior to the invention, random distributions of fillers and porosity in a matrix were relied upon to resemble natural stone.
Natural stones have color variations and a surface texture, which are aesthetic features that are difficult to replicate by imitation stone compositions. The features are not closely resembled by random distributions of fillers and porosity in the imitation stone compositions. Wnat is needed is a process of controlling color variations and surface texture of manufactured imitation stones to replicate, more than merely resemble, the features of natural stones.
U.S. Pat. No. 6,113,995 discloses a process to create particular patterns of pigments in cast cementitious materials. Formulas are set for different imitation stone mixes. Specified amounts of different stone mixes are loaded into a three dimensional array within a holding container. Then the mixes are released from the container into molds where imitation stone patterns form according to the different mixes.
The imitation stone made by previous methods, did not replicate the features of actual natural stones. Accordingly, the imitation stone had many differences in appearance compared to the appearance of actual natural stones. Further, natural stones differ from one another, especially when mined from different quarries. Since the methods for making imitation stone prior to the invention did not replicate natural stone features, the differences among the natural stones could not be accurately replicated.
The invention relates to an imitation stone siding, and a method for making the imitation stone siding without a need to arrange fabrication materials in random distributions or in controlled mixes.
According to the invention, a method is disclosed for manufacturing an imitation stone siding that replicates the features of actual natural stone, especially replicating different colors and replicating the surface texture or topography.
According to an embodiment of the invention, imitation stone is made by shaping a mold cavity with a surface that follows a topography of one or more natural stones. Pigments are applied at different locations on the mold cavity to replicate different colors of each natural stone and a distribution of the different colors at different locations on the topography. An imitation stone material is formed in the mold cavity to replicate the topography of each natural stone on the imitation stone material, and to transfer the pigments to the imitation stone material.
According to another embodiment of the invention, mapping data are obtained to correspond with different colors at different locations on the surface of each of the one or more natural stones. Accordingly, the mapping data replicates authentic height variations and authentic color variations of the surface of each of the one or more natural stones.
According to a further embodiment of the invention, a mold die is made by a machine controlled micro machining operation or selective etching operation using the mapping data as machine control data. Thus the mold die is made with a surface that follows the topography of each of the one or more natural stones.
Another embodiment according to the invention includes, a process step of making a pattern directly from the topography one or more natural stones. The pattern is made on a mold die. Thus the mold die is made with surface texture features of each of the one or more natural stones.
Another embodiment of a method according to the invention includes a process step of making one or more imitation stones in a mold, according to the following process steps. A mold is made with a mold topography that follows the topography of one or more natural stones. Pigments of different colors are applied to the mold topography, replicating the colors of each of the one or more natural stones at different heights of the stone's topography. Then imitation stone material is formed in the mold to transfer the imitated stone's topography to the imitation stone material. Further the pigments are transferred to the surface of the imitation stone material. Thereby, the method according to the invention produces one or more imitation stones that replicate the topography and surface texture of one or more natural stones. Further, each imitation stone replicates the color variations at different heights of the natural stone's topography, i.e., different colors at different heights.
A further embodiment of a method according to the invention includes a process step of making imitation stone in a mold, by transferring a replicating topography of the mold to imitation stone material that is formed in the mold, and transferring pigments on the mold to the imitation stone material to replicate the colors at different heights on the topography of each of one or more natural stones.
This description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.
According to the invention, a method is described for manufacturing each of the imitation stones (102) by replicating the actual surface texture or topography of each of one or more natural stones. Further, according to an embodiment of the invention, a method is described for manufacturing each of the imitation stones (102) by replicating the color variations and color patterns of a natural stone's topography. Each of the imitation stones (102) is a copy or replicate of an individual natural stone. The natural stone can have a weathered smooth surface or a quarried surface formed along quarrying fractures. Further, each imitation stone is a copy or replicate of the color variations at different heights of the natural stone's topography, i.e., different colors at different heights. Previous to the invention, imitation stone could merely imitate natural stone, without being a copy or replicate of the natural stone.
According to an embodiment of the invention, first, the surface topography of an individual natural stone is mapped, according to different colors at different heights of the topography. A scanning reflecting light microscope that is known in the industry scans the surface texture of an individual natural stone to create a data map of the surface texture. Such data maps can be displayed on a computer display terminal together with the different colors of the surface. The data maps are comprised of data representing different heights of the topography at different locations on the surface of the natural stone, together with additional data representing different colors at different heights of the topography. Thus, the data represents the topography and colors of the natural stone at different locations on the topography. Further, using the data, different pigments are selected to replicate the different colors of the natural stone. The pigments are used to color the imitation stones (102).
Alternatively, according to another embodiment of the invention, data mapping is conducted by manual observation and recording the observations as data. The surface topography of an individual stone is mapped by visual observation of the different colors at different heights of the topography. Written records of the visually observed different colors and topography are maintained as data representing the actual topography and actual colors of the natural stone.
Alternatively, the surface of the mold cavity (202) of
Further, the mold cavity (202) includes a recess (210) around the replicated profile (208) for making an imitation mortar joint (110) at the profile (208) of an individual imitation stone (102). According to an embodiment of the invention, the depth of the mold cavity (202) is in a range of 0.25 inches to 3.0 inches. Although the mold cavity (202) is disclosed as replicating a single natural stone (204), the invention herein applies to a single mold cavity (202) that replicates one or more natural stones (204) in the same mold die (200). For example, the mold die (200) replicates one or more natural stones (204) to make a panel for siding (100) of various sizes, for example, in the range of 1 foot square to 4 feet by 10 feet rectangular. Further, for example, one or more natural stones (204) are replicated either with or without mortar joints (110) therebetween. When mortar joints (110) surround the natural stones (204) that are being copied or replicated, then the imitation mortar joints (110) are made as replicates of the mortar joints (110) surrounding the natural stones (204). Alternatively, when replicating one or more natural stones (204) that do not have mortar joints (110), the imitation mortar joints (110) can be created by shaping the mold cavity (202) with one or more recesses (210) to simulate mortar joints (110). Further, alternatively, the recesses (210) can be omitted from the mold cavity (202), to replicate a number of stones in a mortar free stone wall.
In practice, the entire section of imitation stone siding (100) having a number of individual imitation stones (102) can be made in a single mold cavity (202), by making the mold cavity (202) replicate a number of individual natural stones (204). According to another embodiment of the invention, recesses (210) are provided to form replicated mortar joints (108), that would resemble a laid-up stone wall.
The first imitation stone material is, for example, a high density foamed polyurethane. For example, the first imitation stone material in a fluent state is injected into the clearance between the first mold surface (216) and the mold cavity (202), according to an injection molding operation, followed by molding the imitation stone material until it cures. Alternatively, the first imitation stone material is poured into the mold cavity (202), followed by, closing the first lid (212), according to a casting operation that casts the imitation stone material. The material is cured to a solidified state by the application of heat and by the application of pressure in the mold cavity (202) between the mold die (200) and the mating mold die (212). Following curing of the surface layer (218), the mold die (200) is opened by pivoting the first mating mold die (212) about the hinge (214), counter-clockwise in
For example, the second imitation stone material is either injected into the clearance between the closed second lid (212) and the mold cavity (202), or is poured into the mold cavity (202), followed by, closing the second lid (212). The second material composition is cured by the application of heat and pressure in the mold cavity (202) between the mold die (200) and the mating mold die (212) comprised of the second lid (212). Following curing of the interior section (226) to a solidified state, and bonding thereof to the surface layer (218), the mold die (200) is opened by pivoting the second mating mold die (220), clockwise in
With reference to
With reference to
Since the pigment (300a) is desired to remain solely on the one topography height (300), excess pigment is removed from shallower heights (302), (304) and (306) of the topography. With reference to
With reference to
When the durable surface layer (218) disclosed by
According to a preferred embodiment of the invention, the in-mold pigment is a coating that chemically reacts with the material of the durable surface layer (218) during formation in the mold cavity (202) is available from Red Spot Paint & Varnish Co., Inc., Evansville, Ind., USA. The top layer or durable surface layer (218) is a polyurethane-polyurea hybrid foam forming material commercially available from Hehr International Polymers, Decatur, Ga., USA. The inner section (226) of the imitation stone is a brand name “Elastopor” polyurethane foam forming material commercially available from BASF Corporation, Mount Olive, N.J., USA. Fiber reinforcement and fire retardant are added to the materials of the surface layer (218) and the inner section (226) prior to formation in the mold cavity (202). For example, the fiber reinforcement comprises chopped glass strands commercially available from CertainTeed Corporation, Blue Bell, Pa., USA. The fire retardant is an iso- or di- or tri-propanolamine commercially available from Dow Chemical Company, Midland, Mich., USA.
Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.
