Molding process and apparatus for producing unified composite structures

Abstract

A method of forming a unitary, composite structural member, and a member formed in accordance with the process. The process involves stitching a plurality of warp knit panel sections together to generally form a plurality of independent panel sections. The sections are placed within the dies of a molding tool such that a rib portion of each section aligns. Inflatable bladders are then slipped into voids formed in between the various panel sections of the assembly. The bladders are inflated to hold the panel sections in the shape of the final product and to hold the rib portions in contact with one another. Resin is then infused into the panels that make up the assembly. The assembly is then cured. When the panels are removed from the molding tool a unitary, complexly shaped, composite structural member is formed.

1 . A unitary composite structure comprising: 
 a first composite panel having a first rib portion secured thereto;    a second composite panel secured to a second rib portion;    said first and second composite panels being simultaneously infused with a resin while placed within a molding tool, wherein said rib portions interengage, and then said composite panels are cured for a desired curing time, wherein upon completion of said curing said first and second composite panels form a unitary composite structure having a rib structure formed by said first and second rib portions linking said first and second composite panels together.    
     
     
         2 . The structure of  claim 1 , wherein at least one of said first and second composite panels are formed from a warp knit fabric.  
     
     
         3 . The structure of  claim 1 , wherein a plurality of inflatable bladders are placed within the tool and inflated prior to infusing the first and second composite panels with resin, to assist in holding portions of said first and second composite panels in contact with interior surfaces of said molding tool, and said rib portions in contact with one another.  
     
     
         4 . The structure of  claim 1 , wherein one of said rib portions comprise a pair of flaps adapted to receive therebetween an end portion of the other one of said rib portions.  
     
     
         5 . The structure of  claim 1 , wherein at least one of said composite panels comprises a plurality of subpanels stitched together.  
     
     
         6 . The structure of  claim 5 , wherein said first composite panel is stitched to an edge of said first rib portion.  
     
     
         7 . A unitary, composite structure, comprising: 
 a first flexible panel having a first flexible rib portion secured thereto so as to be able to extend non-parallel to said first flexible panel;    a second flexible panel having a second flexible rib portion secured thereto so as to be able to extend non-parallel to said second flexible panel; and    wherein said rib portions interengage one another when at least one inflatable bladder is placed between said flexible panels and adjacent said rib portion, and said bladder is inflated; and    wherein said flexible panels and said interengaging rib portions become rigid to form said composite structure after being placed in a mold, infused with a resin, and then allowed to cure.    
     
     
         8 . The structure of  claim 7 , wherein said first flexible panel and said second flexible panels comprise composite panels.  
     
     
         9 . The structure of  claim 7 , wherein said first and second flexible rib portions each comprise composite rib portions.  
     
     
         10 . The structure of  claim 7 , wherein a plurality of inflatable bladders are placed between said first and second flexible panels.  
     
     
         11 . The structure of  claim 7 , wherein said flexible panels and said flexible rib portions form an elongated, hollow portion within said structure.  
     
     
         12 . The structure of  claim 7 , wherein one of said rib portions includes a hole for enabling said inflatable bladder to be removed after said structure is cured.  
     
     
         13 . The structure of  claim 7 , wherein said flexible panels and said flexible rib portions form an internal I-beam structure when said structure is viewed end-wise.  
     
     
         14 . A composite structure comprising: 
 a pair of composite panels disposed generally parallel to one another;    a plurality of composite rib panels stitched to the composite panels to form support ribs;    wherein said support ribs are formed when a plurality of inflatable bladders are placed between said panels and inflated to urge said composite rib panels to engage to form said support ribs; and    wherein said structure is formed when said composite panels and said composite rib panels are placed within a mold, infused with a resin and then allowed to cure.    
     
     
         15 . The structure of  claim 14 , wherein said composite rib panels comprise a tongue-in-groove engagement arrangement.  
     
     
         16 . The structure of  claim 14 , wherein at least one of said composite rib panels includes a hole for enabling at least one of said inflatable bladders to be removed after said structure is formed.  
     
     
         17 . The structure of  claim 14 , wherein support ribs define a plurality of elongated voids within said structure running co-extensively with said composite panels.  
     
     
         18 . The structure of  claim 14 , wherein at least one of said composite rib panels includes a pair of flaps adapted to fold over onto and sandwich an end portion of a different, mating one of said composite rib panels, as one of said inflatable bladders is inflated.  
     
     
         19 . The structure of  claim 14 , wherein a plurality of internal voids are formed within said structure, and voids being defined in part by said composite rib panels.