Abstract:
A modular composite panel and system of panels provides an aesthetically pleasing wallboard, ceiling, or other covering for an interior surface of a building. The panels are made from a hardened gypsum based skin moulded with a lower density backing material. The panels have a three dimensional relief and can be abutted together to form a system of panels. An experienced installer can use a filler that has a vinyl or acrylic additive to fill the seams between the panels. The installer can then sand the seams and adjacently located regions, as necessary, to create a continuous, seamless three-dimensional surface. Each panel is capable of receiving paint or texture, or being cut, trimmed or machined.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This description generally relates to decorative panels for covering an interior surface, and methods of manufacturing the same.  
         [0003]     2. Description of the Related Art  
         [0004]     Coverings for interior surfaces in both residential and commercial buildings are well known in the art. Coverings include wallboard, ceiling tiles, or wainscoting, for example. Interior surfaces such as walls and ceilings are typically covered with gypsum-based plaster panels sandwiched between two sheets of board cover paper, sometimes referred to as “drywall” or “plaster-board” (gypsum is also known as “calcined stucco”; whereas the chemical name for gypsum is calcium sulfate hemihydrate). Wallboard typically has a flat, smooth, papered-covered surface and slightly beveled edges. The beveled edges are abutted together during installation and the seams between the wallboard panels are typically filled with a standard joint compound and taped with drywall tape. The seams between adjacent sheets of wallboard disappear after the process of taping, mudding, and finishing. Drywall is usually fastened to the studs or joists of the walls or ceiling, respectively, with drywall screws.  
         [0005]     Traditionally, wallboard has been designed to not only be flat, but also to facilitate a smooth installation and finish. In the end, the state of the art in wallboard technology continuously teaches toward smoother and smoother surfaces, seamless connections, and clean corners.  
         [0006]     At the same time, molded structures exist that allow individuals to install arches, posts and capitols and other architectural features, and to caulk or otherwise join such features to the surrounding wall and/or ceiling to add distinction to the room. These architectural features are then painted along with the walls and ceiling, giving the room a more complex and interesting appearance.  
         [0007]     One example of a decorative covering for an interior surface is wainscoting. Wainscoting is typically installed over the top of wallboard on interior walls for decorative purposes. The material used for the wainscoting is most often wood, but can also be wood fiber particleboard, or straw particleboard. Straw particleboard uses waste wheat straw as the raw material.  
         [0008]     Another gypsum-based material, such as glass-fiber reinforced gypsum, has been used to make shell castings for decorating ceilings, columns, and other interior objects. These shell castings are typically formed as one continuous shell and shaped using female molds. The mold can be made using any known means, such as CAD-CAM mold-making software. The gypsum-based material is sprayed or otherwise applied to the interior surface of the mold. Once dry, the structure is removed from the mold, the exterior surface of the structure having the desired shape. The interior of the structure is typically hollow and rough. Brackets and other support structure are used to support the shell castings. Rods, links, or truss members are then used mount the shell castings to an underlying surface, for example a wall, ceiling, or column.  
         [0009]     A company named Marrotte, located just outside of Paris, France, produces several other types of decorative coverings for interior surfaces (http://www.marotte.fr/english/english_index_asp.htm). One type of decorative covering is a panel created by weaving strips of wood veneer. Another type of decorative covering is a wood panel that has a sculptural design carved or laser cut into the wood panel. In comparison to drywall, for example, these panels are much more expensive because they must be custom ordered, machined or hand carved, and they are made out of wood.  
       SUMMARY OF THE INVENTION  
       [0010]     In one aspect, the invention includes a composite panel for covering an interior surface, the panel having a hardened structural skin cast from a gypsum based material; and a backing member having a first surface and a second surface, the first surface moulded to the structural skin, the second surface having a substantially flat portion, the backing member made from a material having a lower density than that of the structural skin; and wherein the panel formed by the moulded structural skin and backing member includes a perimeter and a three-dimensional relief pattern, the amount of relief being variable over the area of panel relative to the substantially flat portion of the second surface of the backing member.  
         [0011]     In another aspect, the invention includes a modular system of composite panels for covering an interior surface of a building, in which the system includes a plurality of panels with each panel abutted with at least one other panel, each panel having a hardened structural skin cast from a gypsum based material and a backing member having a first surface and a second surface, the first surface moulded to the structural skin, the second surface having a substantially flat portion, the backing member made from a material having a lower density than that of the structural skin, wherein the panel formed by the moulded structural skin and backing member includes a perimeter and a three-dimensional relief pattern, the amount of relief being variable over the area of panel relative to the substantially flat portion of the second surface of the backing member; and adjacent panels forming a seamless transition from one panel to the next where the three-dimensional relief pattern is configured to produce a continuous, sculpted, visible surface covering the interior surface after the panel seams have been finished.  
         [0012]     In a further aspect, the invention includes a method of manufacturing a modular, composite panel by directing a gypsum based material into a mould to create a cast, hardened structural skin with a three-dimensional relief pattern; and moulding a backing member to the skin, the backing member made from a material having a lower density than that of the skin, a first surface of the backing member being affixed to the skin during the moulding process.  
         [0013]     In yet a further aspect, the invention includes a method of affixing modular, composite panels to an interior surface of a building by placing a first panel on the interior surface; attaching the first panel to the interior surface; placing a second panel on the interior surface and adjacently locating the second panel with the first panel; aligning a three-dimensional relief pattern of the first panel with the three-dimensional relief pattern of the second panel; attaching the second panel to the interior surface; filling a seam between the adjacent panels with a filler; and sanding the filled seam and proximately located regions on the panel to provide a seamless appearance.  
         [0014]     In another aspect, a panel for covering an interior surface includes a first surface having a substantially flat portion; a second surface opposed from the first surface, the second surface having a three-dimensional relief pattern, the amount of relief being variable over the area of panel relative to the substantially flat portion of the first surface; and a plurality of terminal edges defining the perimeter of the panel. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is an isometric view of a room where one of the interior surfaces in the room is covered with panels according to one illustrated embodiment.  
         [0016]      FIG. 2A  is a front plan view of a three-dimensional relief pattern, according to another embodiment of the present invention.  
         [0017]      FIG. 2B  is a front plan view of a three-dimensional relief pattern, according to another embodiment of the present invention.  
         [0018]      FIG. 2C  is a front plan view of a three-dimensional relief pattern, according to another embodiment of the present invention.  
         [0019]      FIG. 2D  is a front plan view of a three-dimensional relief pattern, according to another embodiment of the present invention.  
         [0020]      FIG. 3  is an isometric view of a panel having a three-dimensional relief pattern according to one illustrated embodiment.  
         [0021]      FIG. 4  is a front plan view of the panel of  FIG. 3 .  
         [0022]      FIG. 5  is a cross-sectional view of the panel of  FIG. 3  taken along line  5 - 5  of  FIG. 4 .  
         [0023]      FIG. 6  is a front plan view of another panel having a three-dimensional relief pattern and having reinforced edges according to one illustrated embodiment.  
         [0024]      FIG. 7  is a cross-sectional view of the panel of  FIG. 6  taken along line  7 - 7  of  FIG. 6 .  
         [0025]      FIG. 8  is a front plan view of another panel having a three-dimensional relief pattern according to one illustrated embodiment.  
         [0026]      FIG. 9  is a cross-sectional view of the panel of  FIG. 8  taken along line  9 - 9  of  FIG. 8 .  
         [0027]      FIG. 10  is a flow diagram of a method for manufacturing a panel according to one embodiment of the invention.  
         [0028]      FIG. 11  is a flow diagram of a method for installing panels on an interior surface according to one embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0029]     In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one skilled in the art will understand that the invention may be practiced without some of these details. In other instances, well-known structures, installation techniques and manufacturing techniques associated with interior surface coverings such as wallboard, ceiling panels, or wainscoting, etc., may not be shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments of the invention.  
         [0030]     The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.  
         [0031]     This description initially presents a general overview of a system of modular, composite panels attached to an interior surface of a building and then provides a structural description of an individual modular, composite panel according to one embodiment of the invention. Next, the manufacturing process of the individual panel is described. Finally, the system of panels and the installation thereof is revisited and described in more detail.  
         [0000]     Modular Panels  
         [0032]      FIG. 1  illustrates cut away view of a room  10  having interior surfaces  18  such as walls  12 , a floor  14 , and a ceiling  16  with one of the walls  12  covered by a system of panels  20  according to one embodiment of the invention. The surface underneath the system of panels can be existing wallboard or some other substrate.  
         [0033]     The system of panels  20  forms a continuous, three-dimensional relief pattern where the pattern is visibly seamless over the covered area. The edge  22  of the covered wall  12  is exposed for illustration purposes only.  
         [0034]     When the panels are aligned (e.g., side edge to side edge or top edge to bottom edge) the system of panels  20  can create a continual or flowing visual effect. The pattern can flow multi-directionally, vertically, horizontally, diagonally, and/or some other direction across the panel. In addition, the actual pattern design is not limited to the illustrated embodiment.  FIGS. 2A through 2D  illustrate a number of other possible patterns such as a “zen” pattern ( FIG. 2A ), a “lamps” pattern ( FIG. 2B ), a “big dots” pattern ( FIG. 2C ), and a “tvees” pattern ( FIG. 2D ).  
         [0035]      FIGS. 3 and 4  illustrate a panel  30  having a reinforced skin  24 , a backing member  26 , a number of mounting points  28 , and a perimeter defined by terminal edges  29 . The reinforced skin  24  can be made from a gypsum-based material. In one embodiment of the present invention, the reinforced skin  24  is made from a fiber reinforced gypsum (FRG) for added tensile strength. The embedded fibers may be glass, cellulose, polyester, carbon, or any number of strength-improving fibers. In the illustrated embodiment, the reinforced skin  24  is made from glass-fiber reinforced gypsum (GFRG), but can be referred to as GRG (glass reinforced gypsum) or FRG. The reinforced skin  24  has an outer surface  32  and an inner surface  34  ( FIG. 5 ). The outer surface  32  is generally smooth while the inner surface  34  can have a rougher surface finish. The rougher surface finish of the inner surface  34  can enhance the attachment of the backing member  26  when the backing member  26  is moulded with the reinforced skin  24 .  
         [0036]     The backing member  26  is preferably made from a material having a lower density than FRG. A preferred material for the backing member  26  is a mixture of low-density pottery plaster and perlite. A typical low density pottery plaster that mixes well with perlite is No.  1  Casting Plaster sold by US Gypsum Company. Perlite is not a trade name but a generic term for naturally occurring siliceous rock. An interesting property of perlite is that when it is heated in its crude form to a suitable temperature, approximately 1600 degrees Fahrenheit (871 degrees Celsius), the crude perlite expands from about 4 to 24 times its original volume. This expansion gives perlite its light weight. The perlite, as utilized in the present invention, is purchased in an already expanded form. In an alternative embodiment, either the reinforced skin  24 , the backing member  26 , or both can be made from a cement-based material such as portland cement.  
         [0037]     In addition, the backing member  26  has a first surface  33  and a second surface  35 . The first surface  33  is moulded with and in contact with the reinforced skin  24 . The second surface  35  is configured to be substantially flat for mounting the panel  30  to a flat, interior surface.  
         [0038]     In addition to the reinforced skin  24  and the backing member  26 , the panel  30  can have mounting points  28  according to one embodiment of the invention.  FIG. 5  illustrates a cross sectional view of a panel  30  with one partially reinforced mounting points  28  on the right hand side of the panel and a fully reinforced mounting point  28  on the left side of the panel. Both types of reinforced mounting points  28  are depicted in  FIG. 5  for illustrative purposes, although it is likely that an individual panel  30  would be configured with only one type of mounting point  28 . The reinforced mounting point  28  structurally performs like a grommet  36  by reinforcing the opening  38  therethrough.  
         [0039]     In the illustrated embodiment, the grommet  36  is integrally formed or cast with the reinforced skin  24  and extends from the inner surface  34  of the skin  24 . The extended length of the grommet  36  from the inner surface of the skin  24  can be varied. In one embodiment illustrated on the right hand side of  FIG. 5 , the grommet  36  extends partly through the opening  38  to only partially reinforce the panel  30 . In another embodiment also illustrated in  FIG. 5 , the grommet  36  extends substantially through the opening  38  to better reinforce the panel  30 . One skilled in the art will appreciate and understand that the grommet  36  can be integrally cast with the skin  24  and consequently be made from GFRG. Additionally or alternatively, the grommet may be a separate structural member that could be inserted and bonded in the opening  38  after the skin  24  is cast or during the casting process.  
         [0040]     Still referring to  FIG. 5 , the peaks  40  and valleys  42  of the three-dimensional relief pattern  44  from one location to the next over the area of the panel  30  can be variable in height or depth relative to the second surface  35  of the backing member  26 . The dimensional offset or relief between the peaks  40  and the valleys  42  is sufficient to produce a three-dimensional appearance to an observer who is standing across the room from where the panel  30  is located. For example, in one embodiment of the invention, the maximum relief is in the range of about 1.0 inch to 2.0 inches.  
         [0041]      FIGS. 6 and 7  illustrate a panel  30  according to another embodiment of the invention.  FIG. 6  depicts a panel  30  with a different three-dimensional relief pattern  44 .  
         [0042]      FIG. 7  is a cross sectional view of the panel of  FIG. 6  having flanges  46  extending from the reinforced skin  22  where the flanges  46  form the terminal edges  29  of the panel  30 . In the illustrated embodiment, the flanges  46  are integrally cast with the reinforced skin  22  and are thus comprised of FRG, same as the skin material. However, one skilled in the art will appreciate and understand that the flanges  46  may be bonded to the terminal edges  29  of the panel  30  after the panel is constructed. In an alternative embodiment, the perimeter of the panel  30  is interference fit into or bonded with a strip (not shown), for example a metal or a ceramic strip.  
         [0043]      FIG. 8  illustrates a one-piece panel  100  having a front surface  102 , a back surface  104 , a number of mounting points  106 , and a perimeter defined by terminal edges  108 . The panel  100  can be made from a gypsum-based material, a cement-based material, or some other type of casting material. If a gypsum-based material is used, it may further contain fibers for added strength. A cement-based material as portland cement can also be used to form the panel  100 . The front surface  102  in the illustrated embodiment has a three-dimensional relief pattern  110 .  FIG. 9  illustrates a cross sectional view of the one-piece panel  100 .  
         [0000]     Manufacture of a Modular Panel  
         [0044]      FIG. 10  is a flow diagram illustrating a method  200  of manufacturing a modular, composite panel  30 . In  202 , either a new mould can be created or a pre-made mould can be purchased or re-used. In  204 , the three-dimensional relief pattern  44  is designed. In  206 , computer numerically controlled (CNC) machining techniques are employed to produce the mould. CNC machining techniques for making moulds and other components are well-known in the art. Creating new moulds can be done quickly, inexpensively, and efficiently with CNC machining techniques. In addition, the variety of three-dimensional relief patterns  44  that can be created is nearly limitless.  
         [0045]     In  208 , a pre-made mould can be purchased or re-used. After selecting the mould, a casting material is poured into the mould to create a cast, hardened structural skin  24  with a three-dimensional relief pattern  44  that conforms with the mould. In one embodiment, the casting material is a gypsum based material, which may include fibers for added strength. In another embodiment, the casting material is a cement-based mixture such as portland cement. The casting material is directed into the mould when it is in a slurry or viscous liquid form. Typically, the structural skin  24  sufficiently hardens within four to ten minutes after it is directed into the mould. The surface of the skin in contact with the mould becomes the visible side of the skin after the panels are assembled and installed.  
         [0046]     In  210 , the backing member  26  is moulded to the skin  24 . The backing member  26  is made from a material having a lower density than that of the skin. As discussed above, the material used for the backing member  26  can be a mixture of low density pottery plaster and perlite. As a further option, fibers can be included in the mixture.  
         [0047]     In one embodiment of the present method, the backing member  26  is formed with the structural skin  24  by pouring a slurry of the backing member mixture onto the sufficiently hardened structural skin  24 . Thus, one surface of the backing member  33  ( FIG. 5 ) becomes affixed to the skin  24  during the moulding process such that the backing member  26  and the skin  24  become joined after the backing member  26  has set-up.  
         [0048]     The height and width tolerance of the panel  30  during manufacturing is preferably held to ±⅛ of an inch. The tolerance for the thickness of the panel  30  is preferably held to ± 1/16 of an inch. However, one skilled in the art will appreciate and understand that these tolerances may be narrowed or opened depending on the capability of the manufacturing facility.  
         [0000]     Installation of Modular Panels on an Interior Surface  
         [0049]      FIG. 11  is a flow diagram illustrating a method  300  of installing modular panels  30  onto an interior surface  18 . In  302 , a panel  30  is placed onto an interior surface  18 . In  304 , the panel  30  is attached to the interior surface  18  with fasteners, adhesive, or other well-known attachment techniques. In one embodiment, as previously described, the panel  30  can have pre-cast mounting points  28 . The panel  30  can be attached to existing drywall using drywall anchors, which are well known in the art. If a portion of the panel  30  is attached to a wall stud, for example, the amount of torque applied to the fastener should be controlled as the fastener is seated into the panel  30 , otherwise there is a risk that the structural skin  24  may crack if the fastener is torqued into the stud with too much force. Additionally and alternatively, if other mounting points  28  are desired aside from the pre-cast mounting points  28 , additional mounting points  28  can be provided by using a countersink drill-bit. When drilling additional mounting points  28 , care should be taken to not crack or break through the structural skin  24  panel. Further, the panel  30  should be hung plumb and level if installed on a vertical surface, such as a wall  12 .  
         [0050]     In  306 , a second panel can be placed on the interior surface  18  and adjacent to the first panel. The second panel  30  can be placed on either side, above, or below the first panel  30 . It is not necessary that the terminal edges  29  of the panels  30  be in actual physical contact. In some environments, it may be necessary to leave a gap between the terminal edges  29  of the panels  30  to allow the panels  30  to better flex with the wall  12 , for example. Building flexure is a common phenomenon. In addition, a gap between the panels  30  also permits some play in the panel system  20  due to thermal or humidity effects.  
         [0051]     In  308 , one way of aligning the panels  30  is to align the three-dimensional relief patterns  44  of each panel  30 . Aligning the relief patterns  44  assures that the-overall panel system  20  will have a continual, flowing visual appearance when the installation is complete. A mismatch tolerance of ± 1/32 of an inch between adjacent panels is provided as a guideline, however an experienced installer working with a more lenient three-dimensional pattern  44  may be able to adjust for a larger mismatch without adversely affecting the overall appearance of the panel system  20 . In some patterns, for example the pattern of  FIG. 2A , the mismatch tolerance should be monitored closely in order to permit the stems of the three-dimensional leaf pattern to be adequately aligned with the adjacently located panels  30 .  
         [0052]     Either in addition to or alternative to aligning the relief patterns, the terminal edges  29  of the first and second panels  30  can be aligned. However, one skilled in the art will appreciate that because the dimensions of the panels  30  can vary slightly from one panel to the next during fabrication, as discussed above, the primary goal during installation is to match the three-dimensional patterns  44 .  
         [0053]     Once the panels  30  are sufficiently aligned, the second panel  30  is attached to the interior surface  18  in  310 . Attachment of the second panel  30  is accomplished in a manner similar to that described above to attach the first panel  30 .  
         [0054]     In  312 , which is optional, a bonding agent is used in the seam or gap between the two adjacently located panels  30 . The bonding agent can be a polyurethane glue or a construction mastic such as LIQUID NAILS®. The terminal edges  29  of the adjacently located panels  30  are joined when a liberal bead of glue is applied to joint or seam and allowed to set. After-the glue has set, excess glue can be cleaned off and if any glue extends beyond the surface of the structural skin  24 , then this glue can be trimmed off, if necessary, with a snap-off tool or mat knife. Alternatively, the joint can be sanded to scuff up the surface near the seam and the glue surface, to remove any dry glue residue, to reduce any variation between the surfaces  24  of the panels  30 , or any combination of the above.  
         [0055]     In  314 , the seams between the adjacent panels  30  are filled with a filler. The use of drywall tape and standard drywall joint compound should not be used for the installation of the panels of the present invention. The preferred filler should have a vinyl or acrylic additive, be softer than the structural skin  24 , and be easily sanded. Fillers such as DAP Vinyl Spackling or DAP Fast &#39;N Final Lightweight Spackling, both commonly available, work well for filling the seams between adjacent panels  30 . After the seams are filled, the seams and the surrounding area are sanded in  316 . The sanding process blends out the seam and provides the panel system with the continual, sculptural effect where the individual panels  30  become a panel system  20 . Some final operations that can be performed on the panels  30  are sealing the panels  30  with a polyvinyl acetate based sealer and painting the panels  30 . Flat paint is preferable so that the interior room lighting does not highlight minor imperfections, which is more likely if gloss or semi-gloss paint is used.  
         [0000]     Advantages of Modular Panels  
         [0056]     One aspect of using a gypsum based product is that gypsum-based products have been known to protect materials from the heat of a flame for up to two hours. The superior fire properties of gypsum result because gypsum based products act like a thermal regulator when exposed to flame. Although the panels of the present invention are not intended to substitute for existing wallboard, the gypsum based panels can still provide an enhanced thermal barrier on a surface.  
         [0057]     One advantage of the composite panels of the present invention is that the panel&#39;s visible surface is hard, solid, and ceramic-like because the dense rocklike plaster used for the reinforced skin  24  is fine and smooth. In addition, the panels can provide enhanced sound proofing between adjacent rooms. The hard and irregular surface, provided by the three-dimensional pattern on the panel, can tend to diffuse reflected sound within a room.  
         [0058]     Yet another advantage of the gypsum-based panels of the present invention is that they are comprised of nontoxic minerals and are not subject to hazardous polymerization, which means that they do not off-gas like plastic during the manufacturing process. In fact, gypsum is used in several major brands of toothpaste and chalkboard chalk. Likewise, perlite is chemically inert and has been used on pressure and rotary vacuum filters in the food industry.  
         [0059]     When the reinforced skin  24  is combined with the backing member  26 , which is made from the lower density material, the weight of the panel can be significantly reduced versus making the entire panel  30  from only the gypsum-based material. Lighter panels are easier-to install and may also reduce the stress around the mounting points  28  of the panel after installation, for example during building flexure.  
         [0060]     The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the invention in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims, but should be construed to include all gypsum-based composite panels and panel systems and methods for manufacturing and installing such panels in accordance with the claims. Accordingly, the invention is not limited by the disclosure, but instead its scope is to be determined entirely by the following claims.