Abstract:
A decorated floor panel having a core with a top surface and an opposite bottom surface; a decorative layer coupled to the top surface of the core, the decorative layer having a desired aesthetic appearance; and a wear layer coupled to and substantially covering the decorative layer for protecting the decorative layer. The wear layer has an exposed wear surface with depressions therein of a variable depth below the wear surface, the depressions being arranged to display a desired texture pattern. It is noted that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims pursuant to 37 C.F.R. § 1.72(b).

Description:
This application is a continuation of, and claims priority to and the benefit of U.S. patent application Ser. No. 09/770,581, entitled “Textured Laminate Flooring,” filed on Jan. 26, 2001 now abandoned, and Ser. No. 10/283,002, entitled “Textured Laminate Flooring,” which was filed on Oct. 29, 2002 now abandoned, which are incorporated in its entirety in this document by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to flooring panels for use in commercial, industrial or residential environments. More particularly, this invention relates to flooring panels having an aesthetically pleasing appearance provided by texturing imparted to the surface of the panels. In certain embodiments, the texture is aligned in registration with a visible graphic design displayed by the panel to further enhance the aesthetic appearance of the flooring panel. 
   2. Background Art 
   Various laminates, including high pressure laminates and fiberboard core laminates, are commonly used in flooring applications. Fiberboard core laminates used to manufacture flooring products include a plurality of layers, including a fiberboard or organic composite core section, a decorative layer, and a hard and flat protective wear layer of resin-impregnated melamine material. 
   The wear layer of the laminate in such systems is typically clear, such that the aesthetic appearance, including any color and/or printed image of the decorative layer, is not obscured by the wear layer. Further, the top surface of the wear layer is typically flat, such that the flooring panel exhibits a two-dimensional appearance to the onlooker. Thus, while the decorative layer may exhibit an appearance that simulates “natural” flooring materials such as hardwood or ceramic tile, the typical laminate wear layer simply allows an unobstructed view of the laminate decorative layer, and does not add to or enhance the aesthetic properties of the flooring panel. 
   Some prior art laminate flooring systems have included barely-perceptible indentations imparted to the laminate wear layer to interrupt the aforementioned two-dimensional appearance. Those systems feature shallow indentations of a depth not exceeding 0.25 millimeters (“mm”). Further, the location of individual indentations or the “pattern” of indentations provided in prior art systems are unrelated and unlinked to the aesthetic image provided by the decorative laminate layer. Thus, any indentation pattern in prior art laminate wear layers is not related in any way to the selected aesthetic appearance of the decorative laminate layer. 
   SUMMARY OF THE INVENTION 
   The present invention, in one embodiment, is a decorated floor panel including a core having a top surface and an opposite bottom surface. A decorative layer is adhered to the top surface of the core and, in one embodiment, substantially covers the core. A desired aesthetic appearance, such as a hardwood or ceramic tile appearance, is displayed by the decorative layer of the laminate. Finally, a wear layer is provided over the decorative layer, substantially covering the decorative layer and providing protection from the ambient environment. The wear layer has an exposed wear surface with depressions therein of a variable depth below the wear surface, the depressions being arranged to display a desired texture pattern. 
   In another aspect, the present invention is a decorated floor panel as set forth above, wherein the depressions in the wear surface have a depth of at least 0.50 mm below the nominal surface of the wear layer. In this embodiment, the depressions may all be of a constant depth or, alternatively, of a variable depth as exists for the embodiment discussed above. 
   In yet another aspect, the present invention is a decorated floor panel in which the decorative layer is provided with a decorative pattern. In one embodiment, a plurality of depressions imparted to the wear layer form a desired texture pattern thereon. The relative orientation of the texture pattern and the decorative pattern is controlled such that the depression pattern and the texture pattern are substantially in registration, creating an enhanced, three-dimensional aesthetic appearance to the decorated floor panel. 
   In yet another aspect, the present invention is a floor system comprised of a plurality of individual decorated floor panels assembled together and interlocking with each other by tongue and groove engagement, which is not visible after the floor panels are assembled. 

   
     BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS 
       FIG. 1  is a perspective view of an embodiment of the decorated floor panel according to the present invention. 
       FIG. 1A  is an enlarged fragmentary view of an embodiment of the decorated floor panel of  FIG. 1 , the texture pattern being represented out of registration with the decorative pattern. 
       FIG. 1B  is an enlarged fragmentary view of an embodiment of the decorated floor panel of  FIG. 1 , the texture pattern being represented in registration with the decorative pattern. 
       FIG. 2  is a section taken along lines  2 - 2  in  FIG. 1 . 
       FIG. 3  is a perspective cut-away view of an embodiment of the decorated floor panel according to the present invention. 
       FIG. 4  is a perspective view of a group of decorated floor panels according to the present invention assembled to form a portion of a floor system. 
       FIG. 5  is a section taken along lines  5 - 5  in  FIG. 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, “a,” “an,” or “the” can mean one or more, depending upon the context in which it is used. The preferred embodiment is now described with reference to the figures, in which like numbers indicate like parts throughout the figures. 
   Referring to  FIG. 1 , the present invention, in one embodiment, is a decorated floor panel  10 . In the illustrated embodiment, the panel  10  is manufactured from a laminated material having a fiberboard core. Alternatively, the floor panel  10  of the invention may be manufactured from other materials, including other laminates such as high pressure laminate (“HPL”), which have been marketed under such trade names as Formica and Pergo. Other materials may also be utilized to construct the floor panel, such as other natural, recycled or synthetic materials. 
   The fiberboard core laminate illustrated in  FIG. 3  includes a plurality of discrete layers, including a wear layer  12 , a decorative layer  14 , a core  16  and a backing layer  24 . The illustrated core  16  is preferably manufactured of fiberboard, such as that marketed by companies including Louisiana Pacific, Georgia Pacific, Temple Inland and Weyerhauser. The presently preferred fiberboard core material is formed of high density fiberboard, which is a hardwood/softwood fiber compound compressed at 900-960 kg/m3. The preferred fiberboard core material is usually available in 4 or 5 feet widths and lengths of up to 18 feet. In other embodiments, cores  16  of different materials or having different properties may be utilized, including other timber-based products, such as plywood, chipboard or particleboard. 
   Referring now to  FIGS. 2 and 3 , the core  16  has a top surface  18  and an opposite bottom surface  20 . When installed, the bottom surface  20  of the core  16  faces the underlying subfloor (not shown).  FIG. 3  illustrates an embodiment having an optional backing layer  24  adhered to the bottom surface  20  of the core  16 . Because the illustrated fiberboard core is not completely impervious to moisture and contaminants, such a backing layer  24  may be provided to improve moisture resistance of the floor panel  10 . Additionally, the backing layer  24  may improve structural integrity of the floor panel  10  by increasing overall thickness and reducing the warp and wear tendencies of uncoated core material. In one embodiment, a clear backing layer  24  of melamine, reinforced with aluminum oxide (AlO2) and impregnated with a thermosetting resin, is utilized. In such an embodiment, an optional layer (not shown) may be interposed between the bottom surface  20  of the core  16  and the backing layer  24 . In one embodiment, the optional layer is constructed of paper. The optional layer may display a printed image, such as a trademark, product number or name, or any other desired marking or designation. In other embodiments, backing layers  24  may be constructed of other materials providing suitable moisture resistance, such as phenolic resins or other natural, synthetic or recycled materials. 
   A decorative layer or “decor” layer  14  is adhered, joined, or coupled to the top surface  18  of the core  16  by a chemical adhesive, mechanical connection, or other means known in the art. In the illustrated embodiment, the decorative layer  14  is a sheet of paper that substantially covers the top surface  18  of the core  16 . Thus, in the illustrated embodiment, the top and bottom surfaces  18 ,  20  of the core  16  are covered by the decorative layer  14  and the backing layer  24 , respectively. The visible side of the decorative layer  14 , i.e., the side not adhered to the core  16 , is capable of displaying a desired aesthetic appearance, such as a color or pattern. Virtually any color or pattern may be imparted to the decorative layer  14 . For example, currently contemplated patterns include simulated hardwood flooring and simulated ceramic tile, each in a variety of styles, shades and colors. Currently contemplated simulated hardwood styles include pine, heart pine, cherry, maple, beech, oak and mahogany. Simulated tile appearances are contemplated in a range of styles, including a variety of marble and ceramic tile colors, including groutlines in ceramic tile styles. Other currently contemplated patterns include floral patterns, abstract designs, geometric designs and company logos. Other patterns may be selected by the manufacturer or user according to aesthetic preference or design objectives. 
   As mentioned above, in one embodiment the decorative layer  14  is manufactured from paper that may be impregnated with a thermosetting resin and provided with the desired aesthetic color and/or pattern. In other embodiments that are not shown, other materials may make up the decorative layer  14 , such as real wood veneer, pulverized stone, or other materials. Additionally, it is possible to achieve a similar decorative appearance by either a direct or indirect printing process directly onto the top surface  18  of the core  16 . In such an embodiment, the decorative layer  14  comprises whatever ink, dye, pigment or other marking substance applied to the core  16 . Alternatively, the decorative appearance may be provided by etching, burning or otherwise marring the top surface  18  of the core  16 . Any such treatment that supplies such a decorative appearance on the top surface  18  of the core  16  is contemplated to comprise the decorative layer  14  as defined herein. 
   Referring now to  FIG. 3 , a wear layer  12  is provided over the decorative layer  14 , substantially covering the decorative layer  14  and providing protection from the ambient environment. The wear layer  12  is adhered, joined, or coupled to the decorative layer  14 , just as the decorative layer  14  is joined to the underlying core  16 . In one embodiment, the wear layer  12  is comprised of a melamine sheet, reinforced with aluminum oxide (AlO2) and impregnated with a thermosetting resin. It is preferred, though not required, that the material selected to comprise the wear layer  12  be the same or similar material as that selected to comprise the backing layer  24 , if a backing layer  24  is utilized. Using “matched” materials for those layers has been found to minimize “warping” and “bowing” of the laminate material. 
   Alternatively, a layer of varnish or a UV curable scratch resistant coating may be used in place of the melamine sheet to comprise the wear layer  12 . As further alternatives, other materials providing suitable moisture resistance and resilience to loads and wear to which a floor is subjected may be utilized, such as phenolic resins or other natural, synthetic or recycled materials. 
   After manufacture of the laminate material, the wear layer  12  is substantially transparent, so that the aesthetic appearance of the decorative layer  14  is substantially unobstructed by the wear layer  12 . It has been determined that the inclusion of a wear layer  12  as the outermost layer of the laminate generally improves the resistance of the floor panel  10  to wear, including staining or fading of the aesthetic image imparted to the decorative layer  14 . 
   As illustrated in  FIGS. 2 and 5 , the outermost wear surface  26 , i.e., the top surface of the wear layer  12  that is exposed to the ambient environment, is provided with a textured surface condition. Thus, in addition to the decorative aesthetic image displayed by the decorative layer  14 , further aesthetic effect may be achieved by imparting depressions of a constant or variable depth to the wear surface  26 , arranged to display a desired texture pattern. For example, in the embodiment illustrated in  FIG. 1  in which the decorative pattern is a wood grain, a texture pattern featuring depressions designed to simulate wood grain may be provided. As a further example, in an embodiment in which the decorative pattern is a simulated ceramic tile having tile portions surrounded by groutlines, a texture pattern having an irregular simulated stone texture and roughened or non-smoothed depressions to simulate recessed grout may be provided. These examples are merely illustrative and are not intended to be exhaustive. Other decorative patterns and texture patterns may be selected by the manufacturer or user according to aesthetic preference or design objectives. When referencing depressions, one skilled in the art will appreciate that this term excludes the edges circumscribing the panel and instead encompasses “depressions” within the periphery of the edges. 
   In the embodiment shown in  FIG. 1A , the texture pattern is imparted to the floor panel  10  without regard to the positioning of the decorative pattern. Thus, in this embodiment, the wood grain pattern displayed in the decorative layer  14  (depicted in dashed lines in  FIG. 1A ) does not necessarily “match,” register with, or correspond to the wood grain pattern imparted as three-dimensional texture in the wear layer  12  (depicted in solid lines in  FIG. 1A ). 
   In another embodiment, shown in  FIG. 1B , the texture pattern and the decorative pattern may be controlled during the manufacturing process such that the patterns “match.” In the hardwood floor panel example, therefore, the textured grain pattern may be imparted to wear layer  12  (solid lines) in registration with the visible grain pattern in the decorative layer  14  (dashed lines). In such an embodiment, lines of depression in the wear layer  12  are located adjacent or substantially on top of the printed grain lines in the decorative layer  14  of the laminate, providing an enhanced and more realistic aesthetic appearance. 
   As a further example, “knothole” patterns  30  in the decorative layer  14  are substantially overlaid by correspondingly shaped depressions in the wear layer  12  in  FIG. 1B . Thus, in this embodiment, the hard wood flooring design displayed by the decorative layer  14  includes the visual appearance of at least one knothole  30 . The wear surface  26  has at least one depression therein in registration with the knothole  30 . The knothole  30  may be of a variety of shapes. In one embodiment, the knothole  30  is substantially circular, and the corresponding depression in registration with the knothole  30  is also substantially circular in top plan view. Other embodiments are contemplated in which the knothole  30  has other shapes, such as an oval shape or some irregular shape similar to those found in natural hardwood planks. Such alternate embodiments are within the scope of the present invention. 
   In a currently contemplated hardwood embodiment, the depressions in the wear layer  12  in registration with the decorative pattern are imparted to a depth of at least 0.30 mm below the wear surface  26 . In another contemplated embodiment, the depressions in the wear layer  12  in registration with the decorative pattern are imparted to a depth of at least 0.50 mm below the wear surface  26 . In still another contemplated embodiment, the depressions are imparted to a depth of at least 1.0 mm below the wear surface  26 . In yet other contemplated embodiments, the depressions are imparted to a depth of at least 1.50 mm, 2.0 mm, 2.50 mm, or 3.0 mm, respectively, below the wear surface  26 . The possible width of the depressions is unlimited, but in presently preferred embodiments, widths of between approximately 1.0 mm and 25.0 mm have been utilized. 
   Similarly, in the simulated ceramic tile embodiment shown in  FIGS. 4 and 5 , the texture pattern may be imparted to the wear layer  12  in registration with the image imparted to the decorative layer  14 . In one embodiment, the ceramic tile design of the decorative layer  14  includes the visual appearance of at least one groutline  40 , and the wear layer  12  has at least one depression therein in registration with the groutline  40 . In embodiments where the groutline  40  imparted to the decorative layer  14  is substantially square in shape, the corresponding depression in registration with the groutline  40  is also substantially square in top plan view. In another embodiments, the groutline  40  may be provided in any selected pattern, including but not limited to triangular, hexagonal, octagonal, or other patterns. Such alternate embodiments are within the scope of the present invention. 
   In a currently contemplated simulated ceramic tile embodiment, the depressions in the wear layer  12  in registration with the groutline  40  are imparted to a depth below the wear surface  26  of at least 0.30 mm. In another contemplated embodiment, the depressions in the wear layer  24  in registration with the groutline  40  are imparted to a depth below the wear surface  26  of at least 0.50 mm. In still another contemplated embodiment, the depressions are imparted to a depth below the wear surface  26  of at least 1.0 mm. In yet other contemplated embodiments, the depressions are imparted to a depth of at least 1.50 mm, 2.0 mm, 2.5 mm, or 3.0 mm, respectively, below the wear surface  26 . The possible width of the depressions is unlimited, but in presently preferred embodiments, widths of between approximately 5.0 mm and 10.0 mm have been utilized. 
   Also in simulated ceramic tile embodiments of the present invention, a “rough” simulated stone texture may be imparted to the areas of the wear layer  12  overlaying the simulated stone image  42  in the decorative layer  14 . Further, any recessed depression in the wear layer  12  substantially overlaying the simulated groutline  40  in the decorative layer  14  may be provided with a “rough” simulated grout texture that is non-smooth visually and to the touch. This non-smooth and “rough” appearance more closely emulates the appearance of stone. 
   The selected texture pattern is usually, though not always, imparted to the wear layer  12  in a single manufacturing step, at the time the laminate layers are laminated together. In such an embodiment, the various laminate layers are positioned within a press (not shown) having a caul plate (also not shown) provided with an inverse impression of the selected texture pattern. After the laminate layers are positioned within the press, the caul plate is lowered to contact the wear layer  12  of the laminate. In a single step, under heat and pressure for a selected period of time, the layers are laminated together and the texture pattern is imparted to the wear layer  12  by the action of the caul plate. Through experimentation, it has been noted that satisfactory results may be obtained by the application of between 380-420 psi at between 350° F.-400° F. for a period of 18-60 seconds. These parameters are set forth by way of example only for an approximately 6.0 mm thick melamine wear layer product sold by the Mead Corporation. It is expected that any of these parameters will vary depending on the degree and depth of depressions sought to be imparted to the wear layer or depending on the characteristics of the selected wear layer material. One skilled in the art will appreciate that after experimentation, other parameters may produce similarly satisfactory results. 
   Alternatively, the texture pattern may be imparted to the wear layer  12  in a separate operation, after lamination of the various layers into a single workpiece. 
   The depth to which the wear layer  12  is depressed to provide the full texture patterns may be controlled during the manufacturing process. It is contemplated that to provide the most beneficial texture pattern, depressions of a depth at least 0.25 mm should be imparted to the wear layer  12 . More specifically, depressions of between 0.30 mm and 5.75 mm in depth, more preferably between 1.0 mm and 5.75 mm in depth, and most preferably between 1.5 mm and 5.75 mm in depth, measured from the nominal surface of the wear layer  12 , have been found to provide the greatest aesthetic effect while not diminishing performance of the overall floor system. These ranges are applicable in embodiments in which a melamine wear layer of approximately 6.0 mm thickness, manufactured by the Mead Corporation, is utilized. It has been found that depressions of a depth up to 0.25 mm less than the nominal thickness of such a wear layer  12  may be achieved using the above-described manufacturing methods; that is, if the nominal thickness is 5.0 mm, then the deepest depressions preferably should be no greater than 4.75 mm. In another preferred embodiment, the deepest depressions should be of a depth up to 0.50 mm less than the nominal thickness of the wear layer  12 . 
   It is expected that if other thicknesses, materials or manufacturing methods are selected to comprise the wear layer  12 , different preferred ranges may exist for each selected material. 
   Additional process controls or equipment may be required to manufacture flooring panels  10  according to embodiments of the invention in which substantial registration between the decorative pattern and the texture pattern are required. In a presently preferred embodiment, a short-cycle press manufactured by Wemhoner and operated by Stiles Machinery, 3965 44th St. S.E., Grand Rapids, Mich. 49512 has been found satisfactory for achieving such registration between the decorative pattern and the texture pattern. 
   During the manufacturing process, in one embodiment, the various separate layers are assembled in preparation for lamination. In the embodiment shown in  FIG. 3 , for example, a backing layer  24 , a core  16 , a decorative layer  14  and a wear layer  12  are stacked together before entering the press. Through processing equipment controls such as a single sheet alignment system and electrostatic bonding of the various laminate layers prior to entry into the press, alignment between the decorative pattern displayed by the decorative layer  14  and the texture pattern imparted to the wear layer  12  by the caul plate may be achieved within a tolerance of 0.125 inches. 
   As illustrated in  FIG. 5 , individual floor panels  10  according to the invention may be assembled to form a complete floor system. To facilitate assembly, individual floor panels may be provided with means for interlocking with adjacently placed panels. As shown in  FIG. 1 , each floor panel  10  may include a first pair of parallel sides  50 ,  52  having tongue and groove cuts along the first and second parallel sides  50 ,  52 , respectively. Each such floor panel  10  further includes a second pair of parallel sides  54 ,  56 , perpendicular to each of the first pair of parallel sides  50 ,  52 , also having tongue and groove cuts. Thus, each such floor panel  10  is capable of interlocking engagement with an adjacent panel. Alternatively, locking edge connections, such as that described in U.S. Pat. No. 6,006,486 to Moriau et al. (which is incorporated herein in its entirety by reference), may be utilized to form a floor covering system in which neighboring floor panels  10  are detachably secured to one another through a mechanical interlock. 
   Along the edges of the floor system, perimeter panels may be cut to length as needed to fit the installation environment and fitted with matching trim pieces (not shown) to provide an aesthetically attractive fit adjacent walls, stairs, doorways or other obstructions or transition areas. 
   In a presently preferred embodiment, individual floor panels  10  are manufactured to a width of 11½ inches and a length of 46 1/16 inches, with an approximate thickness of 5/16 inches. One skilled in the art will appreciate that other panel sizes may be used without departing from the scope of the invention. 
   Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims.