Abstract:
A gliding board, for sliding on waters, snow and land, is constructed from polyethylene foam material, in three-ply or more layers of constant density or different densities as a multi-layer core. The application of compound thermoplastic substance in between each layer of the three-ply board core enhances greater bonding characteristics to lamination of foam materials with different properties.

Description:
[0001]     This is a Continuation-in-Part of U.S. Ser. No. 11/103,554 filed Apr. 12, 2005. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to a method of applying compound thermoplastic substances to laminate the core and other layers of a gliding board made from different kinds of foam materials. Particularly, the invention provides an improved bonding characteristic, surface smoothness and efficient manufacture process to a laminated gliding board. The gliding board can be used as a bodyboard, a snow sled, a grass glider, a sand glider or other gliding device for recreational purpose. The unique production method and multi-layers of the board give the advantage of simplification of manufacturing process, minimize the consumption of resources and material production, reducing manufacturing cost, provides a better structure of the board itself together with enhancing its steadfast of the board for providing better safety and comfort performance for end-users.  
       BACKGROUND OF THE INVENTION  
       [0003]     Generally, a gliding board is composed of a plurality of foam layers laminated together. The sandwich concept is based on two ideas increasing the stiffness in bending of a beam or panel and doing so without adding excessive weight. While the core keeps the skins some distance apart from each other and thereby increasing the stiffness, it also bears most of the shear loading. To perform the sandwich concept correctly, the layers composing the skins and the core of a gliding board must be able to transfer the loads. Without a proper bond, the core and skins of the board work as separate beam and the stiffness is lost. This proves proper core and skins bonding is very critical.  
         [0004]     A bodyboard or a snow sled made of a plurality of polyethylene foam layers and polyethylene film layer is typically laminated together by some conventional laminating processes. One conventional process is by heating the layers and the heated surfaces are immediately pressed and fused together by a pair of nip rollers. This laminating process is generally applied for bonding between a polyethylene foam layer to another polyethylene foam layer. Another conventional process of lamination typically applied for bonding between a polyethylene film layer and a polyethylene foam layer is to apply heat to the film with a heated nip roller on the film side and a normal nip roller on the foam side, where the heated nip roller generally contains an engraved pattern of convex and concave area for better heat transfer. The resulting polyethylene film/foam laminate is then often heat laminated onto a standard foam core.  
         [0005]     Both of these laminating processes form a bonding between the two layers by localized collapse and fusion of foam cells on the surface of the respective layers. In order to acquire a good bonding between the two layers, the fusion temperature of materials on the surface of the respective layers has to be within a very narrow temperature range. Otherwise inadequate bonding may result because the surface material on one layer has not heat up to the fusion state. If a higher heating temperature is applied to both surfaces of the layers, excessive melting of the surface material on the layer with a lower fusion temperature may occur. Accordingly, there needs to provide a lamination method with improved bonding strength to bond two polymer foam layers with different fusion temperature caused by difference in polymeric material or density.  
         [0006]     Gliding devices are usually composed of dual-layer with low density of polymer foam material as board core and essentially having a higher density, closed-cell foam material as intermediate layer for better bonding, by heat laminating between the top and bottom sides of board core and top and bottom skin of the boards. Foam material as board core is normally made from low density elastomers, plastics, or other materials with various porosities. Different categories of foams (for examples, polyethylene, polypropylene, ABS, etc.) will have different characteristics. The differences in density, tensile strength, tensile modulus, elongations, tear strength, use temperature, and thermal conductivity, etc. Foams of different grades and densities will have different properties and characteristics. Thus, for adhering foam to foam physically, heat lamination can be carried out only if the two pieces of foam are of the same grade and density. To adhere two pieces of foam of different grades and densities, lamination can only be carried out by chemical technology—bonding adhesives or a kind of chemical substance as a bridge for the lamination.  
         [0007]     Bonding adhesives are basically divided into two categories: physical adhesive and chemical adhesive (hot melt adhesives). Bonding adhesive is the way commonly used in bonding of industrial foam products at large. The advantages of bonding adhesives are that they are simple and effective in processing because hot melt adhesives can be applied under normal temperature. This explains why bonding adhesives are widely used in bonding foam articles. However, bonding adhesives are a kind of material that can be easily and quickly volatiled, and most of them are poisonous and hazardous to the health of human being and natural environment. The object of the present invention is to provide a system for bonding foam layers of different grades and properties together with specific kinds of compound thermoplastic substances. In the course of bonding the compound thermoplastic substance will remain in fusion state and need to be processed or have special treatments according to the grade and property of the foam materials:—
        (i) the melting point of the compound thermoplastic substance is particularly low;     (ii) the degree of adhesion is particularly high;     (iii) the flowing degree of the compound thermoplastic is particularly high;     (iv) the degree of expansion of the compound thermoplastic substance is particularly low (the compound thermoplastic substance cannot be condensed at one location but distribute evenly on the surface of core layers).        
 
         [0012]     Came across continuous investigations and trials, the inventor has found a number of compound thermoplastic substances, either from the finished products sold in the market or those investigated by himself, that can be easily and effectively bonding foam layers of a gliding board.  
       SUMMARY OF THE INVENTION  
       [0013]     It is a principal aspect of the present invention to provide a multi-layer board core of a gliding board constructed by different types of foam materials which will increase the strength characteristics, greater insulation, better impact resistance and stronger resistance to separation.  
         [0014]     In a second aspect, the invention features the core of a gliding board is adhered to a pair backing foams, one on the top of the core and one at the bottom of the core, and the upper backing foam is adhered to plastic film by compound thermoplastic substances and the laminate of these layers forms a panty shield achieving a stronger and a more durable structure and to reduce the effects of styrene attack.  
         [0015]     In a third aspect, the invention provides a reinforcing side rail or a pair of reinforcing side rails to the side surfaces of a multi-layer board structure in order to enhance the bonding strength of a gliding board and to achieve a quicker, better and more efficient way in the construction and to reduce undesirable wastes.  
         [0016]     The invention also allows the use of a variety of foam materials in forming the core and the backing foams of a gliding board. With the application of the compound thermoplastic substances, the invention features a flexible and variable configuration of the core and the backing foam materials of gliding boards in accordance with the purposes and the needs of end-users. The manufacturing process is also simplified by the use of compound thermoplastic substances because manpower to perform trimming works to gliding boards is substantially reduced.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a perspective view of a first embodiment of the gliding board with polyethylene (PE) foam as the core and ethylene vinyl acetate (EVA) foam as the backing foams.  
         [0018]      FIG. 2  is a perspective view of a second embodiment of the gliding board with polystyrene (PS) foam as the core and polyethylene (PE) foam as the backing foams.  
         [0019]      FIG. 3  is a perspective view of a third embodiment of the gliding board with polypropylene (PP) foam as the core and polyethylene (PE) foam or ethylene vinyl acetate (EVA) foam as the backing foams.  
         [0020]      FIG. 4A  is a cross-sectional view of the gliding board deck structure with ethylene vinyl acetate (EVA) foam as the upper backing foam.  
         [0021]      FIG. 4B  is a cross-sectional view of the gliding board deck structure with polyethylene (PE) foam as the upper backing foam.  
         [0022]      FIG. 4C  is a cross-sectional view of a gliding board deck structure with polypropylene (PP) foam as the upper backing foam.  
         [0023]      FIG. 4D  is a cross-sectional view of a gliding board core structure with a reinforcing side rail of polypropylene (PP) foam.  
         [0024]      FIG. 4E  is a cross-sectional view of a gliding board deck structure with a reinforcing side rail of polyethylene (PE) foam.  
         [0025]      FIG. 5A  is a cross-sectional view of a gliding board deck structure with ethylene vinyl acetate (EVA) foam as the upper backing foam.  
         [0026]      FIG. 5B  is a cross-sectional view of a gliding board core structure with a reinforcing side rail of polyethylene (PE) foam.  
         [0027]      FIG. 6A  is a cross-sectional view of a gliding board deck structure with ethylene vinyl acetate (EVA) foam as the upper backing foam.  
         [0028]      FIG. 6B  is a cross-section view of a gliding board deck structure with polyethylene (PE) foam as the upper backing foam.  
         [0029]      FIG. 6C  is a cross-sectional view of a gliding board deck structure with polypropylene (PP) foam as the upper backing foam.  
         [0030]      FIG. 6D  is a cross-sectional view of a gliding board core structure with a reinforcing side rail of polypropylene (PP) foam.  
         [0031]      FIG. 7A  is a plan view of a snow sled of the present invention with handles.  
         [0032]      FIG. 7B  is a plan view of a bodyboard of the present invention.  
         [0033]      FIG. 8  is a perspective view of a gliding board of the present invention with a reinforcing side rail.  
         [0034]      FIG. 9  is a cross-section view of a gliding board structure of the present invention.  
         [0035]      FIG. 10  is a perspective view of a bodyboard of the present invention with a pair of reinforcing side rails and a rear side rail.  
         [0036]      FIG. 11  is a side, cross-sectional, longitudinal view of a gliding board structure of the present invention.  
         [0037]      FIG. 12  is a partially schematic view of the new methodology of viscose of a deck of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]     While the invention will be described in connection with certain preferred embodiments, i.e. bonding foam layers of different densities and properties together with compound thermoplastic substances, it is to be understood that the present invention is not to be limited to the use of one particular kind of compound thermoplastic substance. For example, the compound thermoplastic substance may be varied in accordance with the grades, properties and densities of foam materials composed of the structure of a gliding board. Further, the present invention is not limited to the particular configuration of the gliding boards shown in the figures and may be of any configuration as is known in the art.  
         [0039]      FIG. 1  illustrates a perspective view of a first embodiment of the present invention of a gliding board. This gliding board has eight layers in the configuration wherein three layers of the compound thermoplastic substances are applied alternately for bonding the core  25  of polystyrene foam, the deck and the bottom skin, laminated together.  
         [0040]     Top layer  11  is a graphically-imprinted plastic polymer film. Graphic images are reversely imprinted on the inner surface of layer  11  using any conventional process for printing on polyethylene or polypropylene, such as the corona printing process, in which an electrical discharge temporarily alters the surface structure of the film, allowing inks to adhere to the film. The top surface plastic polymer film  11  has a thickness in the range of 0.02 to 0.15 mm.  
         [0041]     Layer  12  is the first layer of the compound thermoplastic substance (# 1818  or # 2828 ) wherein substance # 1818  includes low density polyethylene, ethylene vinyl acetate and tackifying resin, and substance # 2828  includes Metallocen Catalysced resin and polyethylene. Layer  12  has a thickness in the range of 0.02 to 0.10 mm.  
         [0042]     Layer  13  is the upper backing foam of closed-cell, high density foam of ethylene vinyl acetate. The upper backing foam  13  has a thickness in the range of 1 to 5 mm, and has a stiffness of between 25 and 65 degrees, and preferably 45 degrees.  
         [0043]     Layer  14  is the second layer of the compound thermoplastic substance (# 1818 /# 2828 ). Layer  14  is to be coated onto the inner surface of the upper backing foam  13  after a deck (Layers  11 ,  12  and  13  are bonded together) is formed. Layer  14  has a thickness in the range of 0.02 to 0.10 mm.  
         [0044]     Layer  15  is the core of a gliding board of low density polyethylene foam material. The core  15  has a thickness in the range of 26 to 51 mm and has a density in the range of 1.5 to 4 lb/ft 3 , and preferably a density of 2.2 lb/ft 3 .  
         [0045]     Layer  16  is the third layer of the compound thermoplastic substance (# 1818 /# 2828 ). Layer  16  is coated onto the outer surface of the lower backing foam  17  after the bottom skin (layers  17  and  18  are bonded together) is formed. Layer  16  has a thickness in the range of 0.02 to 0.10 mm.  
         [0046]     Layer  17  is the lower backing foam of closed-cell, high density foam of ethylene vinyl acetate. The lower backing foam  15  has a thickness in the range of 1 to 5 mm, and has a stiffness of between 25 and 65 degrees, and preferably 45 degrees.  
         [0047]     Layer  18  is a bottom protective sheet of polyethylene foam material. Layer  16  has a thickness in the range of 0.04 to 2 mm.  
         [0048]     Adopting the first layer of the compound thermoplastic substance (# 1818 /# 2828 )  12  for agglutination with the plastic polymer graphic film  11  to the upper backing foam  13  of high density ethylene vinyl acetate foam material. A heat lamination method is used for bonding layers  11 ,  12  and  13  together forming the deck of a gliding board. Again, a heat lamination is used for bonding the lower backing foam  17  and the bottom protective sheet  18  together forming the bottom skin of a gliding. To bond the core  15 , the deck and the bottom skin together, the second layer and the third layer of the compound thermoplastic substances  14 ,  16  are coated onto the inner surface of layer  13  and the outer surface of layer  17  respectively before a heat lamination is used for bonding the three spheres. The plastic polymer graphic film  11  extends from the top portion to the polyethylene sheet at the bottom to form the gliding board.  
         [0049]      FIG. 2  shows a perspective view of a second embodiment of the present invention of a gliding board. The core  25  of this gliding board is made from low density polystyrene foam material and it is sandwiched by a pair of backing foams  23 ,  27  of high density polyethylene foam material. Adopting the first layer of the compound thermoplastic substance (# 6868 /# 1818 /# 2828 )  22  for agglutination with the plastic polymer graphic film  21  to the upper backing foam  23 . Compound thermoplastic substance # 6868  includes anhydride-modified ethylene vinyl acetate polymers, substance # 1818  includes ethylene vinyl acetate, tow density polyethylene and tackifying resin, substance # 2828  includes Metallocen Catalysced resin. Layer  22  lays in between layers  21  and  23 . Layer  22  can fill in the gaps between the peaks and valleys of layer  23  to have intimate contact and better bonding. A heat lamination is used for bonding layers  21 ,  22  and  23  forming the deck of a gliding board. Thereafter, a heat lamination is used for bonding layers  27  and  28  together forming the bottom skin of a gliding board. The second layer of the compound thermoplastic substance (# 6868 )  24  is coated onto the inner surface of the upper backing foam  23  and the third layer of the compound thermoplastic substance (# 6868 )  26  is coated onto the outer surface of the lower backing foam  27 , for agglutination with the core  25  of low density polystyrene foam material. A heat lamination method is thereafter used for bonding the core  25  with the deck and the bottom skin, and the plastic polymer graphic film  21  extends from the top portion to the polyethylene sheet  28  at the bottom to form the gliding board.  
         [0050]      FIG. 3  shows a perspective view of a third embodiment of the present invention of a gliding board. The construction of the gliding board in  FIG. 3  is similar to the construction in  FIG. 2 , except that the combination of the core and the backing foams are of different foam materials. The upper backing foam  33  in this preferred embodiment may be polyethylene or ethylene vinyl acetate. The core  35  is a low density polypropylene foam material. A second and a third layer of the compound thermoplastic substances  34 ,  36 , Which have sandwiched the core  35 , may be substance # 2828  or # 6868 .  
         [0051]     For the bond to work correctly, the density of the compound thermoplastic substance ought to be stronger than the foam material it is joining. The essential part of adhering foam to foam, or foam to plastic polymer film, is to fill the surface cells with the adhesive and protection against water intrusion. The serial numbers of the compound thermoplastic substances, namely, # 1818 , # 2828 , # 6868  and # 7878  (which includes anhydride-modified ethylene vinyl acetate polymers, ethylene vinyl acetate and tackifying resin), are assigned by the inventor by reference to the ingredients and specific prescriptions of each of the substances. Each particular compound thermoplastic substance is applied in accordance with the type, density and property of the foam materials that is constituted as the core of the gliding board.  
         [0052]      FIG. 4A  shows a cross-sectional view of the deck structure of the present invention of a gliding board. To bond the top surface plastic polymer film  41 A with the upper backing foam  43 A, a first layer of the compound thermoplastic substance (# 1818 /# 2828 )  42 A is applied to the outer surface of the upper backing foam  43 A for agglutination. The upper backing foam  43 A is made from a high density, closed-cell ethylene vinyl acetate foam material having a thickness of between 1 and 5 mm, and preferably a thickness of 1.3 mm. The upper backing foam  43 A has a stiffness ranging from 25 degrees to 65 degrees, and preferably a stiffness of 45 degrees. A second layer of the compound thermoplastic substance (# 6868 )  44 A is to be coated onto the inner surface of layer  43 A for agglutination with the core  45 D or  45 E of a gliding board.  
         [0053]      FIG. 4B  shows a similar cross-sectional view of the deck structure of the present invention of a gliding board as at  FIG. 4A , but in which a high density polyethylene foam material is adopted as the upper backing foam  43 B. By agglutination of a first layer of the compound thermoplastic substance (# 1818  or # 2828 )  42 B onto the outer surface of the upper backing foam  43 B and by heat lamination, the plastic polymer film  41 B is ready to be bonded with the upper backing foam  43 B forming the deck of a gliding board. Layer  43 B has a thickness in the range of 1 to 5 mm and has a density in the range of 5 to 10 lb/ft 3 , and preferably a density of 7 lb/ft 3 .  
         [0054]      FIG. 4C  shows a similar cross-sectional view of the deck structure of the present invention of a gliding board as at  FIG. 4A , except that the upper backing foam  43 C is a high density polypropylene foam material. Bonding the plastic polymer graphic film  41 C and the upper backing foam  43 C together, with the application of the first layer of the compound thermoplastic substance (# 1818  or # 2828 )  42 C, by heat lamination, a deck is then formed. The second layer of the compound thermoplastic substance (# 6868 ) to thereafter coated onto the inner surface of the deck and ready to be bonded with the core  45 D or  45 E. The upper backing foam  43 C has a thickness in the range of 1 to 5 mm, and preferably a thickness of 3 mm. The upper backing foam  43 C has a density in the range of 3 and 10 lb/ft 3 , and preferably a density of 7 lb/ft 3 .  
         [0055]      FIG. 4D  illustrates a cross-sectional view of the core and bottom skin structure of the present invention of a gliding board. The core of the gliding board  45 D consists of a low density of polystyrene foam material. The core  45 D has a thick thickness of between 26 and 51 mm. To adhere the core  45 D and the lower backing foam  48 D of different densities and properties, a third layer of compound thermoplastic substance (# 2828  or # 6868 )  47 D is coated onto the outer surface of the lower backing foam  48 D for agglutination. The bottom protective sheet of high density polypropylene foam  49 D is bonded to the bottom surface of the lower backing foam  48 D by heat lamination forming the bottom skin of a gliding board. The reinforcing side rail  46 D, which covers the side surfaces of the core  45 D, the lower backing foam  48 D and the bottom protective sheet  49 D, of this preferred embodiment is made from a high density polypropylene foam material. To secure a good bonding between the reinforcing side rail  46 D and the side surfaces of the core  45 D of different foam materials by heat lamination, a layer of the compound thermoplastic substance (# 6868 /# 2828 )  50 D is adopted and coated onto the inside surface of the reinforcing side rail. The bottom protective sheet  49 D has a thickness of between 0.1 to 0.8 mm. The reinforcing side rail  46 D has a density in the range of 3 to 10 lb/ft 3 .  
         [0056]      FIG. 4E  illustrates a similar cross-sectional view of the core and bottom skin structure of the present invention of a gliding board as at  FIG. 4D , except that the lower backing foam  47 E and the reinforcing side rail  49 E are both made from high density polyethylene foam material. The bottom protective sheet  48 E in this preferred embodiment is made from polyethylene foam material and has a thickness of between 0.3 to 2 mm. To adhere the core  45 E and the lower backing foam  47 E of different grades and properties, a third layer of the compound thermoplastic substance (# 2828 /# 6868 )  46 E is coated onto the outer surface of the lower backing foam  47 E for agglutination. To bond the reinforcing side rail  49 E of high density polyethylene foam material with the core  45 E of polystyrene foam by heat lamination, a layer of the compound thermoplastic substance (# 6868 /# 2828 ) is adopted and coated onto the inside surface of the reinforcing side rail. The reinforcing side rail  49 E has a density in the range of 5 to 10 lb/ft 3 .  
         [0057]     The deck structures of the gliding board as shown in  FIGS. 4A, 4B  and  4 C are that each can be freely combined with the core and bottom skin structures of the gliding board as shown in  FIG. 4D  or  4 E.  
         [0058]      FIG. 5A  shows a similar cross-sectional view of deck structure of the present invention of a gliding board as at  FIG. 4A , except that the second layer of the compound thermoplastic substance  54  is substance # 1818 /# 2828 . The application of a different kind of the compound thermoplastic substance is that the core of this preferred embodiment is low density polyethylene foam. Compound thermoplastic substance # 1818  includes low density polyethylene tackifying resin and ethylene vinyl acetate copolymer and substance # 2828  is Metallocen Catalysced resin.  
         [0059]      FIG. 5B  is another cross-sectional view of the core and bottom skin structure of the present invention of a gliding board. The core  55  of this preferred embodiment is made from low density of polyethylene foam material. The core  55  has a density in the range of 1.5 to 4 lb/ft 3  and has a thickness of approximately 26 to 51 mm. The lower backing foam  57  is made from high density ethylene vinyl acetate foam material having a thickness of between 1 and 5 mm, and preferably a thickness of 1.3 mm. Before adhering to the core, a heat lamination is used for bonding the lower backing foam  57  and the bottom polyethylene sheet  58 . Thereafter, to bond the core  55  of low density polyethylene foam with the bottom skin (layer  57  and  58  bonded together), a third layer of compound thermoplastic substance (# 1818  or # 2828 ) is applied and coated onto the outer surface of lower backing foam  57  as the agent for agglutination. The reinforcing side rail  59  is made from high density polyethylene foam material and has a density in the range of 4 to 10 lb/ft 3 , and preferably a density of 6 lb/ft 3 . Whilst the core  55  and the reinforcing side rail  59  are both made from polyethylene foam material, a heat lamination is used for bonding the reinforcing side rail to the side surface of the core without the need of a compound thermoplastic substance.  
         [0060]      FIG. 6A  shows a similar cross-sectional view of the deck structure of the present invention of a gliding board as at  FIG. 5A .  
         [0061]      FIG. 6B  shows a similar cross-sectional view of the deck structure of the present invention of a gliding board as at  FIG. 4B , except that a second layer of the compound thermoplastic substance (# 1818 /# 2828 )  64 B is adopted for adhering the core  65  of the gliding board.  
         [0062]      FIG. 6C  shows a similar cross-sectional view of the deck structure of the present invention of a gliding board as at  FIG. 4C , except that a second layer of the compound thermoplastic substance is not required for adhering the core  65  of the gliding board.  
         [0063]      FIG. 6D  shows a cross-sectional view of the core and bottom skin structure of the present invention of a gliding board. The core  65  in this preferred embodiment is made from a polypropylene foam material and has a density of between 1.5 to 4 lb/ft 3 . Whilst the lower backing foam  66  is also made from a polypropylene foam material, no compound thermoplastic substance is required for adhering the core  65  and the lower backing foam  66 . A heat lamination method is used for bonding the bottom protective sheet  67  of polypropylene foam, the lower backing foam  66  and the core  65 . The reinforcing side rail  68  is made from high density polypropylene foam material and has a density in the range of 3 to 10 lb/ft 3 . The reinforcing side rail  68  is bonded to the side surfaces of the core  65 , the tower backing foam  66  and the bottom protective sheet  67  by heat lamination.  
         [0064]      FIGS. 4A  to  6 D illustrate some of the combinations of the configuration of the present invention of a gliding board but the combinations of the deck, core and bottom skin structure of the present invention are not limited to those illustrated in the foregoing figures.  
         [0065]      FIGS. 7A and 7B  are the plan views of a slow sled and a bodyboard of different designs.  
         [0066]      FIG. 8  is a perspective view of a core structure of the present invention in which a reinforcing side rail  82  of high density polypropylene or polyethylene foam material is adopted surrounding the side surface of the core  81 . The core  81  of this preferred embodiment may be tow density polyethylene, polystyrene or polyethylene foam materials. If the core is made from low density polyethylene foam material, the density of the core is approximately 1.8 to 2.5 lb/ft 3 . If the core is made from low density polystyrene foam material, the density of the core is approximately 22 to 25 times. If the core is made from low density polypropylene foam material, the density of the core is approximately 1.5 to 4 lb/ft 3 .  
         [0067]      FIG. 9  is a cross-sectional view of another preferred embodiment of the present invention in which the core  94  of the gliding board is made from tow density polyethylene and having a density of approximately 1.8 to 2.5 lb/ft 3 . The core  94  is strengthened by a reinforcing side rail  97  of high density polyethylene foam material having a density in the range between 4 and 10 lb/ft 3 . The deck  98  consists of the plastic graphic film  91 , the first layer of the compound thermoplastic substance (# 1818 /# 2828 )  92  and the upper backing foam  93  of ethylene vinyl acetate having a thickness of 1 to 5 mm and a density of 25 to 65 degrees. The bottom surface of the deck  98  is coated with the second layer of the compound thermoplastic substance (# 1818 /# 2828 /# 6868 )  94  as the agent for agglutination between the deck  98  and the core  95 . The surface of the core  95  and the reinforcing side rail  97  will be completely covered by the deck  98  after they are bonded together.  
         [0068]      FIG. 10  illustrates a perspective view of another preferred embodiment of the present invention of a bodyboard. The reinforcing side rail covering the side surfaces of the core is divided into two parts, an upper beveled edge (a chine)  101  and a lowered beveled edge (a rail)  102 , and the side edge at the tail of the board core is covered by a reinforcing side rail at tail  103 .  
         [0069]      FIG. 11  shows a cross-sectional view of a preferred embodiment of  FIG. 10 .  
         [0070]      FIG. 12  illustrates a partial schematic view of the new method of bonding of plastic polymer graphic film  123  to the upper backing foam  124  of the present invention. By shoving the compound thermoplastic substance which contains ethylene vinyl acetate copolymer and tackifying resin (# 1818 ) or Metallocen Catalysced resin (# 2828 ) in the furnace  121  with a high temperature of 180 to 200 degrees, and thereafter passing through a T-die  122  for injection, a layer of compound thermoplastic substance is placed in between the plastic graphic film  123  and the upper backing foam  124  which are both in roll format to be bonded and pressurized by an upper embossing roller (or plain roller)  125  and a lower plain roller  126  for reinforcement of the stiffness of the graphic film to the board core.