Patent Publication Number: US-2015082741-A1

Title: Method of making a floor panel

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from U.S. Patent Application Ser. No. 61/235,742, filed Aug. 21, 2009, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method of making a floor panel, wherein the floor panel comprises a top layer and a bottom layer adhered together in an offset relationship such that a marginal end portion of a top surface of the bottom layer and a marginal end portion of a bottom surface of the top layer are exposed. 
     BACKGROUND OF THE INVENTION 
     Floor panels for use in floating floor systems typically comprise a top layer and a bottom layer adhered together in an offset relationship such that a substantially L-shaped marginal end portion of a top surface of the bottom layer and a substantially L-shaped marginal end portion of a bottom surface of the top layer are exposed. The top layer typically comprises at least one mix layer, a print film, a wear layer, and a top coat. The bottom layer typically comprises at least one mix layer. The bottom layer has a thickness about equal to or greater than the top layer. A ratio of a thickness of the top layer to a thickness of the bottom layer is typically in the range of about 2 or less. For example, the SURFACE SOURCE product sold by Lowe&#39;s Home Centers, Inc. has a top layer with a thickness of about 64 mils (about 1.63 millimeters), and a bottom layer with a thickness of about 61 mils (about 1.55 millimeters). Thus, the ratio of the thickness of the top layer to the bottom layer is about 1.05 (64 mils/61 mils=1.05). 
     In order to assemble the floating floor system, at least one of the marginal end portions of each of the floor panels is provided with an adhesive. The marginal end portion provided with the adhesive is engaged with the marginal end portion of an adjacent floor panel to form the floating floor system. The floor panels may be formed, for example, such that when the floating floor system is assembled on a sub-floor ends of the top layers of the adjacent floor panels substantially abut, while ends of the bottom layers of the adjacent floor panels are spaced apart a desired distance so that a gap is formed there between. Alternatively, the floor panels may be formed, for example, such that when the floating floor system is assembled on the sub-floor the ends of the top layers of the adjacent floor panels substantially abut and the ends of the bottom layers of the adjacent floor panels substantially abut. 
     Because the thickness of the bottom layer is significantly large (about 98 mils (about 2.5 millimeters)), when the floor panels are assembled such that a gap is formed between the ends of the bottom layers of the adjacent floor panels, the gap can telescope through the floor panels thereby significantly altering the aesthetic and structural characteristics of the top layer. For example, the gaps may cause buckling at a top surface of the top layer. Alternatively, when the floor panels are assembled such that the ends of the bottom layers of the adjacent floor panels substantially abut, unwanted gaps or overlapping can occur between the ends of the bottom layers due to deviations in the size of the marginal end portions and/or errors occurring during installation. These unwanted gaps or overlaps can additionally telescope through the floor panel thereby also significantly altering the aesthetic and structural characteristics of the top layer. 
     Additionally, the marginal end portions of the top layer of a first row of the floor panels, which are typically positioned adjacent a wall, remain unsupported when the floating floor system is assembled, because the marginal end portions of the top layer of the first row of the floor panels will not engage with an adjacent floor panel. Thus, because the thickness of the bottom layer is significantly large, the gap occurring between the sub-floor and the marginal end portion of the top layer will also negatively impact the aesthetic and structural characteristics of the top layer. For example, buckling at the top surface of the top layer can occur. Also, because the bottom layer and the top layer comprise mix layers, which contain fillers, the bottom layer and the top layer are prone to absorb moisture thereby further affecting the aesthetic and structural characteristics of the floor panels. This is particularly problematic, since the bottom layer is installed directly on a sub-floor. 
     Still further, because the bottom layer has a thickness greater than the top layer, when the floor panels are stacked, for example, during shipping, a space exists between the marginal end portions of the top layer of the adjacent flooring panels equal to the thickness of the bottom layer. Thus, during shipping, the unsupported marginal end portions of the top layer are prone to bend and/or curl an amount equal to the thickness of the bottom layer. Because of the structural characteristics of the top layer, these bends and/or curls remain in the marginal end portions of the top layer during installation and can thereby significantly alter the aesthetic and structural characteristics of the floor panel. For example, buckling can occur at the top surface of the top layer and/or the bond strength between the marginal end portions of the adjacent floor panels could be negatively affected. 
     In view of the foregoing, there still remains a need to develop a floor panel that overcomes the above-described problems. Additionally, there still remains a need to simplify the manufacturing process for such floor panels and reduce the expense associated therewith. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention relates to a method of making a floor panel comprising: providing an adhesive on a release member; laminating or marrying the release member to a bottom layer such that the adhesive is between the release member and the bottom layer; removing a portion of the release member to expose an area of the adhesive; and adhering a top layer to the area such that the top layer is offset with respect to the bottom layer in a direction of length and width and a marginal end portion of a top surface of the bottom layer and a marginal end portion of the bottom surface of the top layer is exposed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a floor panel according to an embodiment of the invention. 
         FIG. 2  is a schematic illustration of a method of attaching a bottom layer of the floor panel to a release member of the floor panel to form a continuous sheet. 
         FIG. 3  is a schematic illustration of a method of cutting the continuous sheet into strips having a desired width. 
         FIG. 4  is a schematic illustration of an alternative method of cutting the continuous sheet into strips having a desired width. 
         FIG. 5  is a schematic illustration of a method of cutting the strips to a desired length. 
         FIG. 6  is a schematic illustration of a stripping jig. 
         FIGS. 7  is a schematic illustration of the stripping jig with the strip positioned therein prior to removal of a portion of the release member. 
         FIG. 7A  is a perspective view of the stripping jig with the strip positioned therein prior to removal of the portion of the release member. 
         FIG. 8  is a schematic illustration of the removal of the portion of the release member. 
         FIG. 8A  is a perspective view of the removal of the portion of the release member. 
         FIG. 9  is a schematic illustration of the strip with the portion of the release member removed. 
         FIG. 10  is a schematic illustration of an assembly jig. 
         FIG. 11  is a schematic illustration of the assembly jig with the strip positioned therein prior to attachment of a top layer. 
         FIG. 11A  is a perspective view of the assembly jig with the strip positioned therein prior to attachment of the top layer. 
         FIG. 12  is a schematic illustration of a method of attachment of the top layer. 
         FIG. 12A  is a perspective view of the method of attachment of the top layer. 
         FIG. 13  is a perspective view of a method of applying further pressure to the floor panel. 
         FIG. 14  is a schematic illustration of the floor panel. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
       FIGS. 1-3  show a floor panel  10  according to an embodiment of the invention. As shown in  FIG. 1 , the floor panel  10  comprises a top layer  11 , a bottom layer  12 , and a release member  13 . The top layer  11  may be formed, for example, from a substantially flexible sheet material, such as plastic, vinyl, polyvinyl chloride, polyester, or combinations thereof. The top layer  11  has a top surface  14  with a visible decorative pattern  17  and a bottom surface  15 . In the illustrated embodiment, the top layer  11  comprises at least one mix layer  16 , a print film provided with the visible decorative pattern  17 , a wear layer (not shown), and a top coat (not shown), respectively. It will be appreciated by those skilled in the art that although the top layer  11  is shown and described herein as comprising multiple layers that the top layer  11  may alternatively comprise a single layer. Additionally, the types of layers constituting the top layer  11  and the visible decorative pattern  17  could be varied depending on the desired characteristics of the top layer  11 . 
     As shown in  FIG. 1 , the top layer  11  has a thickness T 1  of about 20-200 mils (about 0.508-5.08 millimeters), preferably about 60-180 mils (about 1.524-4.572 millimeters), and more preferably about 80-150 mils (about 2.032-3.810 millimeters). In the illustrated embodiment, the top layer  11  is substantially rectangular in shape and has a length L 1  of about 36 inches (about 91.4 centimeters) and a width W 1  of about 6 inches (about 15.2 centimeters). However, it will be appreciated by those skilled in the art that the geometrical shape and the length L 1  and the width WI of the top layer  11  may be varied depending on the desired dimension and geometrical configuration of the floor panel  10 . For example, the top layer  11  may alternatively have a substantially square shape. 
     As shown in  FIG. 1 , the bottom layer  12  has a top surface  18  and a bottom surface  19 . The bottom layer  12  may be formed, for example, from a film or tape comprising plastic, vinyl, polyvinyl chloride, polyester, polyolefin, nylon, or combinations thereof. The bottom layer  12  may also include recycle material, such as post industrial or post consumer scrap. The film or tape may be rigid or flexible and is preferably moisture resistant or waterproof. Additionally, the film or tape may be capable of being delivered or shipped in a roll. In the illustrated embodiment, the bottom layer  12  comprises a single layer of rigid black polyvinyl chloride film. Alternatively, the bottom layer  12  could comprise multiple layers, such as two layers of film laminated with a mat, such as a glass mat or polyethylene terephthalate mat, there between. The bottom layer  12  could also be provided with at least one of a continuous or discontinuous ink layer, antimicrobial layer, sound deadening layer, cushioning layer, slide resistant layer, stiffening layer, channeling layer, mechanically embossed texture, or chemical texture. 
     As shown in  FIG. 1 , the bottom layer  12  has a thickness T 2  less than the thickness T 1  of the top layer  11 . The thickness T 2  of the bottom layer  12  is, for example, about 1-60 mils (about 0.0254-1.524 millimeters), preferably about 6.5-12 mils (about 0.1651-0.3048 millimeters), and more preferably about 8 mils (about 0.2032 millimeters). A ratio of the thickness T 1  of the top layer  11  to the thickness T 2  of the bottom layer  12  is about 5 or greater, preferably about 10-100, and more preferably about 10-25. The bottom layer  12  has a length L 2  and a width W 2  the same as the length L 1  and the width W 1  of the top layer  11 . Thus, in the illustrated embodiment, the bottom layer  12  is substantially rectangular in shape and has the length L 2  of about 36 inches (about 91.4 centimeters) and the width W 2  of about 6 inches (about 15.2 centimeters). However, it will be appreciated by those skilled in the art that the geometrical shape and the length L 1  and the width W 1  of the bottom layer  12  may be varied depending on the desired dimension and geometrical configuration of the floor panel  10 . For example, the bottom layer  12  may alternatively have a substantially square shape. 
     As shown in  FIG. 1 , the bottom surface  15  of the top layer  11  is laminated to the top surface  18  of the bottom layer  12  by an adhesive  20 . The adhesive  20  may be, for example, any suitable adhesive, such as a hot melt adhesive, a pressure sensitive adhesive, or a structural and/or reactive adhesive. In the illustrated embodiment, the adhesive is a pressure sensitive acrylic adhesive. The adhesive  20  may have, for example, a bond strength of at least 25 force-pounds, and more preferably about 25-30 force-pounds after having been heat aged for about 24 hours at 145 degrees Fahrenheit. In the illustrated embodiment, the adhesive  20  is provided on substantially an entirety of the top surface  18  of the bottom layer  12 . The adhesive  20  may be applied to have a thickness, for example, of about 1-2 mils (about 0.0254-0.0508 millimeters). It will be appreciated by those skilled in the art, however, that the thickness of the adhesive  20  may vary depending on the texture of the bottom surface  15  of the top layer  11  and the texture of the top surface  18  of the bottom layer  12  in that a substantially smooth surface would require less of the adhesive  20  due to better adhesion and bond strength. 
     The top layer  11  is adhered to the bottom layer  12  so that the top layer  11  is offset from the bottom layer  12  in a direction of the length L 1 , L 2  and the width W 1 , W 2 . In other words, opposing first ends  21  of the top layer  11  are offset in the direction of the length L 1 , L 2  from opposing first ends  23  of the bottom layer  12  an offset distance D 1 , D 2  and opposing second ends  22  of the top layer  11  are offset in the direction of the width W 1 , W 2  from opposing second ends  24  of the bottom layer  12  an offset distance D 3 , D 4 . The offset distances D 1 , D 2 , D 3 , D 4  are substantially the same. In the illustrated embodiment, the offset distances D 1 , D 2 , D 3 , D 4  are, for example, about 1 inch (about 2.5 centimeters). It will be appreciated by those skilled in the art, however, that the offset distances D 1 , D 2 , D 3 , D 4  may be varied depending on the desired configuration of the floor panel  11 . Examples of possible variations in the offset distances D 1 , D 2 , D 3 , D 4  are set forth, for example, in U.S. patent application Ser. No. 12/412,419, filed Mar. 27, 2009, which is hereby incorporated by reference in its entirety. Because the adhesive  20  is provided on substantially the entirety of the top surface  18  of the bottom layer  12 , due to the offset of the top layer  11  relative to the bottom layer  12 , a substantially L-shaped marginal end portion of the top surface  18  of the bottom layer  12  remains exposed to form an adhesive surface  25 , and a substantially L-shaped marginal end portion of the bottom surface  15  of the top layer  11  remains exposed to form an attachment surface  26 . 
     As shown in  FIG. 1 , the release member  13  is positioned adjacent to the substantially L-shaped marginal end portion of the top surface  18  of the bottom layer  12  to cover the adhesive surface  25  during shipping of the floor panel  10  and prior to the installation thereof. In the illustrated embodiment, the release member  13  is a flexible sheet corresponding in size and shape to the substantially L-shaped marginal end portion of the top surface  18  of the bottom layer  12 . It will be appreciated by those skilled in the art, however, that the size and shape of the release member  13  may be varied, as long as the release member  13  adequately covers the adhesive surface  25 . The release member  13  may be made, for example, from any known suitable release material, such as a poly or silicone coated paper, a plastic sheet, a polymer film, or other material that enables the release member  13  to be quickly and easily removed from the adhesive surface  25  during the installation of the floor panel  10 . The release member  13  may additionally be provided with a tab (not shown) that extends from the release member  13  in order to increase the ease of removal of the release member  13  from the adhesive surface  25  during the installation of the floor panel  10 . 
     A method of making the floor panel  10  will now be described in greater detail with reference to  FIGS. 2-13 . As shown in  FIG. 2 , a continuous sheet of the release member  13  and a continuous sheet of the bottom layer  12  are provided. The release member  13  and the bottom layer  12  may be provided, for example, in rolls. The adhesive  20  is applied to a surface of the release member  13 . The adhesive  20  may be applied using any known application methods, such as spraying, roll coating, or air knife coating. The release member  13  provided with the adhesive  20  is then laminated or married to the top surface  18  of the bottom layer  12  such that the adhesive  20  is arranged between the release member  13  and the bottom layer  12  to form a continuous sheet  30  consisting of the bottom layer  12 , the adhesive  20 , and the release member  13 . Additionally, prior to lamination or marrying, it is conceivable that the bottom layer  12  could be annealed. 
     As shown in  FIG. 3 , the continuous sheet  30  consisting of the bottom layer  12 , the adhesive  20 , and the release member  13  is then cut into strips  31 . The strips  31  are formed by slitting the continuous sheet  30  substantially parallel to a direction of tension  32  of the bottom layer  12 . Each of the strips  31  is cut to the width W 2 . When the strips  31  are formed by slitting the continuous sheet  30  substantially parallel to the direction of tension  32  of the bottom layer  12 , the direction of tension  32  of the bottom layer  12  is substantially perpendicular to the width W 2  of the bottom layer  12 . The continuous sheet  30  may be slit into the strips  31  either manually or by using conventional converting and stripping machines. Alternatively, as shown in  FIG. 4 , the strips  31  may be formed by slitting the continuous sheet  30  substantially perpendicular to the direction of tension  32  of the bottom layer  12 . When the strips  31  are formed by slitting the continuous sheet  30  substantially perpendicular to the direction of tension  32  of the bottom layer  12 , the direction of tension  32  of the bottom layer  12  is substantially parallel to the width W 2  of the bottom layer  12 . Thus, when assembled to the top layer  11  (described below), the top layer  11  is capable of counteracting the tension in the bottom layer  12  thereby enhancing performance of the floor panel  10 . As shown in  FIG. 5 , after the continuous sheet  30  has been cut into the strips  31  having the width W 2 , the strips  31  are then cut to the length L 2 . The strips  31  may be cut to the length L 2  either manually or using conventional sheeting machines. 
     As shown in  FIG. 6 , a stripping jig  33  is provided for removing a portion of the release member  13  in order to expose the adhesive  20  for attachment of the top layer  11  to the bottom layer  12 . The stripping jig  33  comprises a base  34 . The base  34  may be substantially rectangular in shape and may be formed, for example, from a substantially flat metal plate. The base has first sides  35  and second sides  36  that extend substantially perpendicular to the first sides  35 . A substantially L-shaped abutment member  37  is provided along one of the adjacent first and second sides  35 ,  36  of the base  34 . The abutment member  37  has an abutment edge  38  for abutting the bottom layer  12 . The abutment member  37  may be formed, for example, from a substantially flat metal plate. A substantially L-shaped cutting member  39  is provided on a top surface of the abutment member  37 . The cutting member  39  has a cutting surface  40  provided on a cutting edge  41  thereof. The cutting member  39  is provided on the top surface of the abutment member  37  such that the cutting edge  41  extends from the abutment edge  38  on the first side  35  of the base  34  the offset distance D 3  and extends from the abutment edge  38  of the second side  36  of the base  34  the offset distance Dl. Additionally, because the cutting member  39  is provided on the top surface of the abutment member  37 , a space  42  is created between the base  34  and the cutting member  39  that has a height substantially equal to a height of the abutment member  37 . 
     As shown in  FIGS. 7 and 7A , one of the strips  31 , which has already been cut to the width W 2  and the length L 2 , is inserted into the space  42  in the stripping jig  33 . The strip  31  is inserted into the space  42  until one set of the adjacent first and second ends  23 ,  24  of the bottom layer  12  substantially abuts the abutment edge  38  of the abutment member  37 . As shown in  FIGS. 8 and 8A , as the strip  31  is securely held in the stripping jig  33 , a portion  43  of the release member  13  is pulled away from the bottom layer  12  thereby releasing the release member  13  from the adhesive  20 . As the release member  13  is pulled, the release member  13  is cut by the cutting edge  41  on the cutting surface  40  of the cutting member  39 . As a result of the removal of the release member  13 , the adhesive  20  is transferred to the bottom layer  12 . Once the release member  13  has been cut from the bottom layer  12 , the strip  31  is removed from the stripping jig  33 . As shown in  FIG. 9 , as a result of the removal of the portion  43  of the release member  13 , the top surface  18  of the bottom layer  12  has an exposed area  44  with the adhesive  20 . Additionally, the substantially L-shaped adhesive surface  25  of the bottom layer  12  is formed. 
     As shown in  FIG. 10 , an assembly jig  45  is provided for assembling the top layer  11  to the exposed area  44  on the top surface  18  of the bottom layer  12 . The assembly jig  45  comprises a base  46 . The base  46  may be substantially rectangular in shape and may be formed, for example, from plastic, wood, or metal and may be machined. The base  46  has first sides  47  and second sides  48  that extend substantially perpendicular to the first sides  47 . A substantially L-shaped support member  49  is provided along one of the adjacent first and second sides  46 ,  47  of the base  46 . The support member  49  has an abutment surface  50  for abutting the bottom layer  12 . The support member  49  may be formed, for example, from plastic, wood, or metal and may be machined. The support member  49  has a stepped portion  51  with a rear abutment wall  52 . The stepped portion  51  extends inward from the abutment surface  50  on the second side  48  of the base  46  the offset distance D 2  and extends from the abutment surface  50  on the first side  47  of the base  46  the offset distance D 4 . 
     As shown in  FIGS. 11 and 11A , the strip  31 , which has the exposed area  44 , is positioned within the assembly jig  45  such that one set of the adjacent first and second ends  23 ,  24  of the bottom layer  12  substantially abuts the abutment surface  50  of the support member  49  on the sides of the exposed area  44 . As shown in  FIGS. 12 and 12A , the top layer  11 , which has already been cut and formed by methods well known in the art, is positioned in the stepped portion  51  such that one set of the first and second ends  21 ,  22  of the top layer  11  substantially abuts the rear abutment wall  52  and is aligned therewith. The top layer  11  is then pressed onto the exposed area  44  with the adhesive  20  to adhere the top layer  11  to the bottom layer  12  in an offset relationship. The bottom layer  12  with the top layer  11  adhered thereto is then removed from the assembly jig  45 . As shown in  FIG. 13 , after removal from the assembly jig  45 , a hand roller  60  or other conventional pressure applying process or device may optionally be used to apply additional pressure to the top layer  11  and/or bottom layer  12  in order to better bond the top layer  11  with the bottom layer  12 . Additionally or alternatively, the floor panel  10  could be passed through a laminator. As shown in  FIG. 14 , the floor panel  10  is now completely assembled and ready for packaging. 
     The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.