Composite structural panel

Abstract

An improved composite structural panel and method of fabrication are provided. In one embodiment, the panel generally includes two outer layers or sheets arranged in substantially facing relationship to each other and an intermediate layer spacing the outer layers apart. The intermediate layer includes a generally rigid stiffening or reinforcing core that preferably is bonded to outer layers to form a unified composite structure. In one embodiment, the core has an open structure defining a plurality of open cells 15. An insulating material is preferably disposed in the cells, and in one embodiment is a rigid foam that structurally reinforces the core 14 and strengthens the panel.

1 . A composite structural panel comprising: 
 a first sheet including a first outer surface and a first inner surface;    a second sheet spaced apart from the first sheet and including a second outer surface and a second inner surface;    a stiffening core element disposed between the first and second sheets and defining a plurality of cells; and    a rigid foam reinforcing material disposed in the cells.    
   
   
       2 . The panel of  claim 1 , wherein the foam reinforcing material is a rigid urethane foam.  
   
   
       3 . The panel of  claim 1 , further comprising a first longitudinally-extending edge formed between the first and second sheets, the edge including a deformable foam portion protruding outwards from the edge and extending longitudinally along the edge.  
   
   
       4 . The panel of  claim 3 , wherein the edge includes a longitudinally-extending window and the foam protrudes outwards through the window to form the deformable foam portion.  
   
   
       5 . The panel of  claim 3 , wherein the edge is made of the same material as the first or second sheet.  
   
   
       6 . The panel of  claim 3 , wherein the edge has an asymmetric shape.  
   
   
       7 . The panel of  claim 1 , wherein the first and second sheets are made of metal.  
   
   
       8 . The panel of  claim 1 , wherein the core element is made of a material selected from the group consisting of paper, resin or polymer impregnated paper, metal, plastic, fiberglass, graphite, and fiber-filled composites.  
   
   
       9 . The panel of  claim 1 , wherein the core element is a rigid or semi-rigid structural member having a plurality of walls defining at least one geometric shape.  
   
   
       10 . The panel of  claim 9 , wherein the geometric shape is selected from the group consisting of triangular, trapezoidal, rhombus, rectangular, square, diamond, pentagon, hexagon, heptagon, octagon, nonagon, decagon, and circular.  
   
   
       11 . The panel of  claim 1 , wherein the core element defines a honeycomb shape.  
   
   
       12 . A composite structural panel comprising: 
 a first facing sheet;    a second facing sheet spaced apart from the first sheet;    a foam material disposed between the first and second sheets; and    a first longitudinally-extending edge having a deformable foam portion protruding outwards from the edge and extending longitudinally along the first edge,    wherein the deformable portion of the first edge is compressible in response to contact by an abutting surface.    
   
   
       13 . The panel of  claim 12 , wherein the first edge includes a longitudinally-extending window and the foam protrudes outwards through the window to form the deformable foam portion.  
   
   
       14 . The panel of  claim 12 , wherein the deformable foam portion has a convex-shaped surface.  
   
   
       15 . The panel of  claim 12 , wherein the foam is a rigid urethane foam.  
   
   
       16 . The panel of  claim 12 , wherein the first edge has a double ship-lap configuration.  
   
   
       17 . The panel of  claim 12 , wherein the edge is made of the same material as the first or second sheet.  
   
   
       18 . The panel of  claim 12 , wherein the edge is roll formed.  
   
   
       19 . A composite structural panel system comprising: 
 a first panel including an internal cavity, an insulating material disposed in the cavity, and a first longitudinally-extending edge having a deformable foam portion protruding outwards from the edge and extending longitudinally along the first edge; and    a second panel including a second longitudinally-extending edge configured to complement the first edge and receive the first edge in an interlocking relationship;    wherein the deformable portion of the first edge compresses upon contact with the second edge when the second edge is inserted into the first edge.    
   
   
       20 . The panel of  claim 19 , wherein the first edge includes a longitudinally-extending window and the foam protrudes from the internal cavity through the window to form the deformable foam portion.  
   
   
       21 . The panel of  claim 19 , wherein the deformable foam portion of the first edge is convex shaped.  
   
   
       22 . The panel of  claim 19 , wherein the second edge includes a deformable foam portion protruding outwards from the second edge and extending longitudinally along the second edge, the deformable foam portions of the first and second edges becoming mutually engaged when the first edge is inserted into the second edge.  
   
   
       23 . A modular structural panel system comprising: 
 a first panel including a pair of spaced apart sheets each having an outer face and at least one first edge longitudinally-extending between the sheets, the edge including an elongated recess and an elongated projection extending along the edge;    a second panel including a pair of spaced apart sheets each having an outer face and at least one second edge longitudinally-extending between the sheets, the second edge including an elongated recess and an elongated projection extending along the second edge, the second edge being complementary to the first edge;    the first and second edges abuttingly interconnected such that the projection of the first edge complementary engages the recess of the second edge and vice-versa to define a joint, the joint including a pressure equalization chamber to balance ambient pressures on opposite faces of the first and second panels.    
   
   
       24 . The panel of  claim 23 , wherein at least the first edge includes a first deformable foam portion protruding outwards from the first edge and extending longitudinally along the first edge, the deformable portion being compressed by the second edge when the first and second edges are interconnected to form a first seal; 
 wherein at least the first edge includes a first longitudinally-extending gasket or sealant, the first gasket or seal being compressed by the second edge when the first and second edges are interconnected to form a second seal, the first and second seals trapping air therein when the first and second edges are interconnected to define a pressure equalization chamber along the panel edges between the first and second seals.    
   
   
       25 . A method of producing a composite structural panel comprising: 
 applying a thickness of foam to a first sheet held in a substantially horizontal position;    setting a core having open cells down into the foam;    contacting the core with the first sheet;    layering a second sheet onto the core to form a panel; and    expanding the foam between the first and second sheets to reinforce to the core.    
   
   
       26 . The method of  claim 25 , wherein the foam is a rigid urethane foam.  
   
   
       27 . The method of  claim 25 , further comprising restraining the first and second sheets from moving relative to each other before expanding the foam.  
   
   
       28 . The method of  claim 25 , further comprising compacting the foam in the open cells.  
   
   
       29 . The method of  claim 25 , further comprising providing pressure to hold the sheets and core together, and heating the panel to cure and harden the foam.  
   
   
       30 . The method of  claim 25 , further comprising hardening the foam.