Abstract:
A reinforced panel comprises at least two strength-providing strands and an insulating filler wherein the filler is situated around the strands such that a combination of the strands and the filler form a cohesive structure. Additionally, a ratio of the strength-providing strands to the filler is such that the panel is strong and rigid and is capable of providing insulation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 60/976,700 filed Oct. 1, 2007 titled “Veneered Bamboo Strand Board Product.” 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of insulated foam panels and more particularly to reinforcing foam with a strength-providing material so as to provide strength and rigidity to the foam. 
       BACKGROUND OF THE INVENTION 
       [0003]    Certain types of foam can be used as an insulating material. However, although foam can provide superior insulating qualities, it does not have the strength and rigidity necessary to create building materials, for example, panels for roofs, walls and the like. Therefore, there is a need to combine an insulating foam with a material that will provide strength and rigidity to the foam so as to make it suitable to use as a building material. 
         [0004]    Wood is generally cut from naturally grown trees. However, trees are limited in supply due to the length of time necessary for a tree to reach maturity. Additionally, the supply of natural wood is limited by the deforestation that is now occurring in many parts of the world. Accordingly, the price of wood has increased, especially in many parts of the world where there is not a large supply of wood. In many countries, people cannot afford to purchase wood to build shelter. 
         [0005]    One approach to this problem has been to produce composite lumber formed of wood products, lignocellulosic materials, or reconsolidated wood products to make lumber products. Generally, producing composite lumber involves splitting, mashing, gluing, and manufacturing artificial wood from wood products to manufacture lumber products such as plywood, particle boards, and chip boards. 
         [0006]    U.S. Pat. No. 4,810,551 filed Mar. 7, 1989 discloses a plywood made from sheets of bamboo. The sheets of bamboo are comprised of strands of bamboo glued together side by side and laminated. In one embodiment, each sheet of bamboo runs perpendicular to the one below or above it, creating the conventional plywood cross grain layering design. In an alternative embodiment, bamboo sheets are stacked on top of one another and glued together with the grain running in the same direction. 
         [0007]    U.S. Pat. No. 5,543,197, which is hereby incorporated by reference, teaches the use of bamboo as a raw material to be used as the primary substance of an artificial wood beam. The bamboo strands are harvested, split open, and dried in long strips. The dried strips have adhesive applied evenly to them, are aligned in a parallel fashion, and are fused under pressure to create an artificial wood beam with qualities similar to that of naturally grown lumber. 
         [0008]    There is a need to combine an insulating foam with a strength-providing material, such as wood or a wood substitute, in such a manner so as to provide insulating building materials for homes, buildings and the like. Additionally, there is a need for a wood substitute, which is less expensive than, more readily available than, and at least as strong as natural wood. 
       SUMMARY OF THE INVENTION 
       [0009]    Accordingly, it is an object of the present invention to provide a building material that uses a strength-providing material in combination with an insulating filler, wherein the building material is less expensive to produce than traditional building materials, but has a similar appearance and possesses properties superior to traditional building materials. 
         [0010]    It is a further object of the present invention to produce a product that utilizes the natural high tensile strength of bamboo for strength and rigidity of the building material. 
         [0011]    It is another object to utilize a filler that provides superior insulating qualities. 
         [0012]    It is still another object of the present invention to combine a strength-providing material and an insulating filler to produce a building material that can be used to construct shelters and the like. 
         [0013]    Finally, it is an object of the present invention to provide a building material that uses a strength-providing material in combination with an insulating filler and can be manufactured to virtually any dimension. 
         [0014]    In accordance with the present invention, all of these objects as well as others not herein specifically identified, are generally achieved by the present reinforced foam panel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Various examples of objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, wherein: 
           [0016]      FIG. 1  is a perspective view of a reinforced foam panel; 
           [0017]      FIG. 2A  shows a layer of strength-providing strands situated parallel to one another; 
           [0018]      FIG. 2B  shows a layer of strength-providing strands situated parallel to one another and in a direction that is perpendicular to the strands shown in  FIG. 2A ; 
           [0019]      FIG. 3  is a perspective view of a reinforced foam panel wherein the strength-providing strands form a matrix with a criss-cross pattern; 
           [0020]      FIG. 4A  shows a layer of strength providing strands with lateral holes therein situated parallel to one another; 
           [0021]      FIG. 4B  shows a layer of strength-providing strands with lateral holes therein situated parallel to one another and in a direction that is perpendicular to the strands shown in  FIG. 4A ; and 
           [0022]      FIG. 5  shows a strength-providing strand with a hole pole situated therein; 
           [0023]      FIG. 6  shows a strength-providing strand with perforated holes situated therein; 
           [0024]      FIG. 7  shows a strength-providing strand with perpendicular pegs extending therefrom; and 
           [0025]      FIG. 8  shows a molding or chute in which strength-providing strands are placed and filler is poured in order to create a cohesive structure. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    While the present invention is susceptible to embodiments in various forms, there is shown in the drawings a number of presently preferred embodiments that are discussed in greater detail hereinafter. It should be understood that the present disclosure is to be considered as an exemplification of the present invention and is not intended to limit the invention to the specific embodiment illustrated. It should be further understood that the title of this section of the present application (“Detailed Description of the Invention”) relates to a requirement of the United States Patent Office and should not be found to limit the subject matter disclosed herein. 
         [0027]    Each of the patents cited herein is incorporated by reference. The use of the article “a” or “an” is intended to include one or more. The foregoing description is intended as illustrative and is not to be taken as limiting. Still other variations within the spirit and scope of this invention are possible and will readily present themselves to those skilled in the art. 
         [0028]      FIG. 1  is a perspective view of a reinforced foam panel  10 . The reinforced foam panel  10  can be used in reinforced foam panels, posts, boards, beams, or the like. In embodiments of the present invention, reinforced foam panels can be used, for example, to build insulated roofs and walls in shelters, homes, buildings, or the like. 
         [0029]    The function of the strength-providing strands, for example  12 ,  14 ,  16 , in the reinforced foam panel is similar to the function of steel rebar in cement. Rebar gives added strength to cement, which would otherwise be a relatively brittle material. Similarly, the reinforced foam panel uses the tensile strength of the strength-providing strands to provide added strength and rigidity to the foam in the reinforced foam panel. In a preferred embodiment, the reinforced foam panels can be used for roof and wall panels. 
         [0030]    In preferred embodiments, the panels have dimensions such that the panels provide superior insulation and are simultaneously easy to work with. Further, the panels have a density ratio of strength-providing strands to filler such that the panels retain the superior strength and rigidity of the strands while providing the superior insulation of the filler. In preferred embodiments, the panels have a thickness from about 4 inches to about 6 inches. 
         [0031]    In embodiments of the present invention the strength-providing strands can be made from wood, plastic, fiberglass, carbon fiber, or a wood substitute. 
         [0032]    Embodiments of the present invention include bamboo as a wood substitute. The bamboo can be harvested, split open, and dried in long strands ranging from ¼ to ¾ inch in width to approximately 5 to 20 feet in length. The strands can be as short as 5 feet or less in small percentages. The dried strips can have adhesive applied evenly to them and they can be aligned with respect to one another. Adhesive applied to the bamboo strips can further enhance the ability of the bamboo to adhere to the filler in the reinforced panel. 
         [0033]    As seen in  FIG. 1 , the strength-providing strands can be situated in a matrix with a perpendicular pattern relative to one another; the perpendicular orientation of the strands results in increased strength of the panels. Specifically, as seen in  FIG. 2A , various strength-providing strands are situated parallel to one another. As seen in  FIG. 2B , additional strength-providing strands are situated parallel relative to one another. When included in the panel  10 , the strands in  FIG. 2A  are placed above the strands of  FIG. 2B  such that the strength-providing strands form a perpendicular pattern relative to one another as seen in  FIG. 1 . 
         [0034]    It is to be understood that the number of strength-providing strands included in each layer of the matrix situated parallel to one another is not a limitation of the present invention. Furthermore, the distance between the strength-providing strands within each layer and the distance between the layers are not limitations of the present invention. The number of strength-providing strands included within each layer situated parallel to one another, the distance between the strands within each layer, and the distance between each layer in the matrix must be such that the reinforced foam panel retains the strength and rigidity of the strength-providing strands. 
         [0035]    Alternately, the matrix may comprise strength-providing strands situated in a criss-cross pattern.  FIG. 3  is a perspective view of a reinforced foam panel  10 ′ wherein the strength-providing strands form a matrix with a criss-cross pattern. The strands can be seen, for example, at  12 ′,  14 ′, and  16 ′. As seen in  FIG. 4A , various strength-providing strands are situated parallel to one another. As seen in  FIG. 4B  various strength-providing strands are situated parallel to one another. In this embodiment, the strands are made with lateral holes, for example,  18   a,    18   b,    18   c,    18   d,    18   e,    18   f,    18   g,    18   h  that extend through the width of the strands. When included in the panel  10 ′, the strands in  FIG. 4A  are placed perpendicular to the strands of  FIG. 4B  such that the strength-providing strands form a perpendicular pattern relative to one another, as seen in  FIG. 3 , and they also intersect one another by passing through the lateral holes. Thus, in this embodiment the strength-providing strands that are situated perpendicular to one another also lie in the same plane for further increased strength. 
         [0036]    It is to be understood that neither the number of strength-providing strands included in each layer of strands situated parallel to one another nor the number of lateral holes within each strand are limitations of the present invention. Furthermore, the distance between the strands within each layer and the distance between the criss-crossed layers of strands are not limitations of the present invention. The number of strength-providing strands included within each layer situated parallel to one another, the number of lateral holes within each strand, the distance between the strands within each layer, and the distance between each criss-crossed layer must be such that the reinforced foam panel retains the strength and rigidity of the strength-providing strands. 
         [0037]    In embodiments of the present invention, the strength-providing strands are textured. Textured strands provide for added strength in the reinforced foam panel. Textured strands also provide for a greater ability to adhere to the filler along the entire length of the strand. Furthermore, the textured strands increase the bond between the strands and the filler. 
         [0038]    Further embodiments of the present invention include hole poles, perforated poles, or perpendicular pegs. As seen in  FIG. 5 , a hole pole  32  can run in a parallel direction relative to the length L of the strength-providing strand and have a diameter less than the diameter of the bamboo strand. A hole pole can be filled with filler to provide for further added strength in the reinforced foam panel, to provide for an even greater ability to adhere to the filler, and to increase the bond between the strength-providing strand and the filler. 
         [0039]    As seen in  FIG. 6 , perforated holes  34 ,  36 ,  38  can be located along the length L of the strength-providing strand, but do not extend through the width of the strand. The perforated holes allow the strength-providing strands to have a greater ability to adhere to the filler. Additionally, the perforated holes increase the bond between the strands and the filler. Thus, the perforated holes provide for further added strength in the reinforced foam panel. 
         [0040]    As see in  FIG. 7 , perpendicular pegs  42 ,  44 ,  46 ,  48 ,  50  can extend from the strength-providing strand in a perpendicular direction relative to the length L of the strand. The pegs can be constricted so as to extend through the width of the strength-providing strand and can extend from one or both sides of the strand. Further, the pegs can be rounded or squared. The perpendicular pegs provide for an even greater ability of the strength-providing strands to adhere to the filler and make the bond between the strands and the filler even stronger. Thus, the perpendicular pegs provide for further added strength in the reinforced foam panel. 
         [0041]    The various embodiments of the strength-providing strands as described above use the natural tensile strength of the strands to provide for added strength in the reinforced foam panel. As discussed above, the strength-providing strand can be made from, for example, wood, plastic, fiberglass, carbon fiber, or a wood substitute such as bamboo. 
         [0042]    Further embodiments of the present invention include a filler. As seen in  FIGS. 1 and 3 , the filler is  11  and  11 ′, respectively. The filler should be thermally insulating and capable of filling the interstices of the matrix formed by the strength-providing strands. In a preferred embodiment, the filler may be a foam. Specifically, the foam may be a rigid, closed cell polyurethane foam. Such a foam is resistant to high temperature and is CFC free. 
         [0043]    Typical physical properties of the foam in a preferred embodiment of the present invention include the following: 
       For Components: 
       [0044]      
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Component A 
                 Component B 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Viscosity, cps at 72° F. 
                 100-200 
                 500 
               
               
                   
                 Specific gravity, at 72° F. 
                 1.24 
                 1.15 
               
               
                   
                 Weight per gallon 
                 10.33 
                 9.58 
               
               
                   
                 Mix ratio 
                 50 
                 50 
               
               
                   
                   
               
             
          
         
       
     
       For Cured Material: 
       [0045]      
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Test Method 
                 Results 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Density 
                 ASTM D-1622 
                 2.4 
               
               
                   
                 Thermal Conductivity 
                 ASTM C-177 
               
               
                   
                 Initial 
                   
                 0.12 
               
               
                   
                 Aged 
                   
                 0.17 
               
               
                   
                 Closed Cell, % Content 
                 ASTM-D-2856 
                 90 
               
               
                   
                 Compressive Strength 
                 ASTM D-1621 
                 50 
               
               
                   
                 Parallel 
               
               
                   
                   
               
             
          
         
       
     
         [0046]    Typical reactivity data of the foam in a preferred embodiment of the present invention includes the following: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Cream time, seconds at 74° F. 
                 40 +/− 5 
               
               
                   
                 Rise time, seconds at 74° F. 
                 160 +/− 30 
               
               
                   
                 Tack-free time, at 74° F. 
                 150 +/− 30 
               
               
                   
                   
               
             
          
         
       
     
         [0047]    The reinforced foam panel can be made with the strength-providing strands and the filler as described herein. It is to be understood that the exact dimensions of the panels and the density ratio of strands to filler are not limitations of the present invention. Rather, the panels have dimensions such that they provide superior insulation and are simultaneously easy to work with. Further, the panels have a density ratio of strength-providing strands to filler such that the panels retain the superior strength and rigidity of the strands while providing the superior insulation of the filler. 
         [0048]    In a method of making a reinforced foam panel, the strength-providing strands, as described by the various embodiments herein, can be situated within a molding or a chute.  FIG. 8  shows strands placed within a molding or chute  20  according to an embodiment of the invention in which the strands are situated perpendicular to one another. It is to be understood that the number of strength-providing strands and their spacing relative to one another are not limitations of the present invention. 
         [0049]    Once the strands are placed, the filler  22 , as described herein, can be poured into the molding or the chute  20 . The strength-providing strands and the filler are fused together under pressure until a cohesive structure is formed. 
         [0050]    In a preferred embodiment, the filler  22  is a polyurethane foam. Thus, the foam  22  expands to fill the empty space and crevices between the strength-providing strands and between the strands and the molding or chute  20 . Once the cohesive structure is removed from the molding or chute  20 , the foam  22  may continue to expand. Any excess foam is removed from the cohesive structure with, for example, a saw. The resulting cohesive structure is then milled into the desired dimensions.