Method of manufacturing composite panels

Abstract

A method of manufacturing solid composite panels utilizes an exothermic foam-forming resin to simultaneously consolidate and cure the heat activated resin of the composite panel without forming a foam-filled part. According to the method, composite fabric layers are laid up on the interior surface of a mold half that conforms to the surface configuration of the finished panel. Once the composite fabric layers are laid up, a flexible bladder is placed over the composite layup and the mold closed. The exothermic foam-forming resin is injected into the bladder within the mold cavity, which generates heat to cure the resin impregnated fabric layers above the cure temperature while simultaneously generating pressure within the cavity to consolidate the fabric layers into a substantially solid void-free composite panel.

1 . A method of manufacturing a composite panel having a first side and a second side comprising: 
 providing a first mold half having an interior surface defining the surface configuration of said first side of said composite panel;    applying at least one fabric layer to said interior surface of said first mold half, said at least one fabric layer comprising a plurality of fibers coated with a heat curable resin;    providing a second mold half;    joining said first mold half and second mold half together to provide a substantially sealed interior volume;    inserting a bladder into said interior volume in contact with said at least one fabric layer;    injecting a catalyzed self-expanding exothermic foam material into said bladder in an amount sufficient to pressurize said interior volume to a predetermined pressure and to simultaneously heat said heat curable resin to a predetermined temperature;    allowing said heat curable resin to cure to form said composite panel; and    separating said foam material from said cured composite panel.    
   
   
       2 . The method of  claim 1  further comprising: 
 applying a non-stick layer between said bladder and said at least one fabric layer.    
   
   
       3 . The method of  claim 2 , wherein: 
 said non-stick layer comprises a woven glass fabric impregnated with a tetrafluoroethylene polymer.    
   
   
       4 . The method of  claim 2  further comprising: 
 allowing said catalyzed self-expanding exothermic foam material to cure into a rigid volumetric body and thereafter detaching said rigid volumetric body from said at least one fabric layer.    
   
   
       5 . The method of  claim 1  further comprising: 
 applying a substantially non-expanding exothermic gel coat layer between said at least one fabric layer and said interior surface of said first mold half.    
   
   
       6 . The method of  claim 1  further comprising: 
 Applying a substantially non-expanding exothermic resin between said at least one fabric layer and said bladder.    
   
   
       7 . The method of  claim 1 , wherein: 
 said heat curable resin is applied to said plurality of fibers of said at least one fabric layer before said at least one fabric layer is applied to said interior surface of said first mold half.    
   
   
       8 . The method of  claim 1 , wherein: 
 said heat curable resin is applied to said plurality of fibers of said at least one fabric layer after said at least one fabric layer is applied to said interior surface of said first mold half.    
   
   
       9 . The method of  claim 1 , wherein: 
 said interior surface defining the surface configuration of said first side of said composite panel comprises a surface defining a residential door skin.    
   
   
       10 . The method of  claim 1 , wherein: 
 said interior surface defining the surface configuration of said first side of said composite panel comprises a surface defining a leg brace.    
   
   
       11 . The method of  claim 1 , wherein: 
 said catalyzed self-expanding exothermic foam material has an exothermic rate sufficient to maintain said heat curable resin at a temperature of least 150 degrees Fahrenheit for a minimum of 30 minutes.    
   
   
       12 . The method of  claim 1 , wherein: 
 said composite panel comprises an orthopedic brace.    
   
   
       13 . The method of  claim 1 , wherein: 
 said composite panel comprises a residential door skin.