High Strength Joining System For Fiber Reinforced Composites

Abstract

The invention relates to joined fiber reinforced composite structures with continuity of fiber reinforcement across adhesive-to-substrate boundaries. Use of a thermal gradient to control the extent of infusion of resin blocking substances into fiber reinforced material, and subsequent resin infusion and resin blocking substance removal, during manufacture of components to be subsequently bonded, provides partially exposed reinforcing fibers which serve to reinforce a subsequently formed joint or boundary.

What is claimed is: 
     
         1 - 11 . (canceled) 
     
     
         12 . A generally sheet form adhesion enhancement material comprising structural fiber with B-stage resin infused into one surface and a flexible water soluble polymer infused into the opposite surface. 
     
     
         13 . A generally sheet form adhesion enhancement material comprising structural fiber infused with a soluble resin blocking substance on one surface and with free fibers on the opposite surface. 
     
     
         14 - 18 . (canceled) 
     
     
         19 . A generally sheet form adhesion enhancement material as described in  claim 12  wherein said flexible water soluble polymer comprises PVA. 
     
     
         20 . A generally sheet form adhesion enhancement material as described in  claim 12  wherein said structural fiber is electrostatically flocked into said material. 
     
     
         21 . A generally sheet form adhesion enhancement material as described in  claim 12  wherein said structural fiber with B-stage resin infused into one surface comprises pre-preg. 
     
     
         22 . A generally sheet form adhesion enhancement material as described in  claim 13  wherein said soluble resin blocking substance comprises PVA. 
     
     
         23 . A generally sheet form adhesion enhancement material as described in  claim 13  wherein said structural fiber is electrostatically flocked into said material. 
     
     
         24 . A method of providing exposed structural fibers at a surface for bonding of an article thereto, said method comprising the steps of:
 establishing a generally sheet form adhesion enhancement material against the surface of a second material,   wherein said second material comprises structural fiber and B-stage resin infused into said surface thereof,   wherein said generally sheet form adhesion enhancement material comprises structural fiber with B-stage resin infused into one surface and a flexible water soluble polymer infused into the opposite surface, and   wherein said step of establishing comprises the step of establishing said B-stage resin infused surface of said generally sheet form adhesion enhancement material to said B-stage resin infused surface of said second material,   said method further comprising the steps of:
 curing said two materials; and 
 removing said flexible water soluble polymer from said opposite surface of said generally sheet form adhesion enhancement material, thereby exposing a portion of said structural fibers thereof at said opposite surface. 
   
     
     
         25 . A method as described in  claim 24  further comprising the step of bonding said article to said opposite surface having exposed fibers. 
     
     
         26 . A method as described in  claim 25  wherein said step of bonding said article comprises the step of bonding a surface of said article having exposed fibers. 
     
     
         27 . A method as described in  claim 24  wherein said B-stage resin infused surfaces both comprise pre-preg. 
     
     
         28 . A method as described in  claim 24  wherein said flexible water soluble polymer comprises PVA. 
     
     
         29 . A method of providing exposed structural fibers at a surface for bonding of an article thereto, said method comprising the steps of:
 establishing a generally sheet form adhesion enhancement material against the surface of a second material,   wherein said second material comprises structural fiber, at least some of which are exposed at a surface thereof,   wherein said generally sheet form adhesion enhancement material comprises structural fiber infused with a resin blocking substance on one surface and with free fibers on the opposite surface, and   wherein said step of establishing comprises the step of establishing said opposite surface, with said free fibers, of said generally sheet form adhesion enhancement material against said surface of said second material with said exposed fibers,   said method further comprising the steps of:
 establishing resin between said generally sheet form adhesion enhancement material and said second material; 
 curing said two materials; and 
 removing said resin blocking substance from said surface of said generally sheet form adhesion enhancement material, thereby exposing a portion of said structural fibers thereof at said surface. 
   
     
     
         30 . A method as described in  claim 29  further comprising the step of bonding said article to said surface of said generally sheet form adhesion enhancement material having exposed fibers. 
     
     
         31 . A method as described in  claim 30  wherein said step of bonding said article comprises the step of bonding a surface of said article having exposed fibers at said surface. 
     
     
         32 . A method as described in  claim 29  wherein said resin blocking substance comprises PVA. 
     
     
         33 . A method as described in  claim 29  wherein said resin blocking substance is soluble. 
     
     
         34 . A method as described in  claim 33  wherein said resin blocking substance is water soluble. 
     
     
         35 . A method as described in  claim 29  wherein said step of establishing resin between said generally sheet form adhesion enhancement material and said second material comprises the step of using a vacuum.