Bladder System for Curing Composite Parts

Abstract

A structure comprising a plurality of walls defining a bladder cavity, the bladder cavity comprises an initial cross section size. A first plurality of wave features provided along at least one of the plurality of walls defining the bladder cavity. In one arrangement, the first plurality of wave features allow the structure to expand from the initial cross section size to a second cross section size after the structure becomes inflated during a composite charge cure, the second cross section size larger than the initial cross sectional size.

We claim: 
     
         1 . A structure comprising:
 a plurality of walls defining a bladder cavity,
 the bladder cavity comprises an initial cross section size, and 
   a first plurality of wave features provided along at least one of the plurality of walls defining the bladder cavity.   
     
     
         2 . The structure of  claim 1 ,
 the first plurality of wave features allow the structure to expand from the initial cross section size to a second cross section size after the structure becomes inflated during a composite charge cure,   the second cross section size larger than the initial cross sectional size.   
     
     
         3 . The structure of  claim 1  wherein the plurality of walls of the structure comprise:
 a bottom wall; 
 a first side wall extending from the bottom wall; 
 a second side wall extending from the bottom wall; 
 a first end wall; 
 a second end wall; and 
 a top wall extending from the first end wall to the second end wall enclosing the structure, 
 the bottom wall, the first side wall, the second side wall, the first end wall, the second end wall, and the top wall defining the bladder cavity, and 
 wherein 
 at least one of the bottom wall, the top wall, the first side wall, the first end wall, the second end wall, or the second side wall comprises the first plurality of wave features. 
 
     
     
         4 . The structure of  claim 2 , wherein
 the first plurality of wave features extend over a length of the at least one of the bottom wall, the top wall, the first side wall, the first end wall, the second end wall, or the second side wall.   
     
     
         5 . The structure of  claim 3 , wherein
 the first plurality of wave features extend over a portion of a length of the at least one of the bottom wall, the top wall, the first side wall, the first end wall, the second end wall, or the second side wall.   
     
     
         6 . The structure of  claim 1 , wherein
 the first plurality of wave features comprise a plurality of uniform wave features.   
     
     
         7 . The bladder of  claim 6 , wherein
 the plurality of uniform wave features each comprise an equivalent radius of curvature.   
     
     
         8 . The structure of  claim 3 , wherein
 at least one of the bottom wall, the top wall, the first side wall, the first end wall, the second end wall, or the second side wall comprises a second plurality of wave features.   
     
     
         9 . The structure of  claim 8 , wherein
 the first plurality of wave features comprise a first radius of curvature and the second plurality of wave features comprise a second radius of curvature,   wherein the first radius of curvature is different than the second radius of curvature.   
     
     
         10 . The structure of  claim 1  further comprising a pressure fitting that is adapted to be coupled with a vacuum source used to inflate the bladder cavity from the initial cross section size to the second cross section size. 
     
     
         11 . A method of curing a charge, the method comprising the steps of
 placing a charge on a tool;   positioning a structure having an initial cross section size in a charge cavity of the charge placed on the tool;   laying up plies over the structure positioned in the charge cavity;   coupling the structure to a vent port;   sealing a vacuum bag over the charge, the layed up plies, the tool, and the structure;   drawing a vacuum;   initiating a debulking process of the charge by inflating the structure;   beginning to expand the structure from the initial cross section size to a second cross section size, larger than the initial cross section size;   creating a plurality of micro-buckles within the structure;   increasing an effective pressure that is applied to an inside radii of the charge;   finalizing debulk; and   curing the charge.   
     
     
         12 . A multilayered bladder system for use in curing of a composite charge defining an internal cavity, the bladder comprising:
 a bladder outer layer,
 the bladder outer layer defining a top wall, a bottom wall, a first sidewall, 
 and a second side wall, wherein the first sidewall and the second sidewall extend between the top wall and the bottom, 
   a bladder first inner layer,
 the bladder first inner layer defining a top wall, a bottom wall, a first sidewall, and a second side wall, wherein the first side wall and the second side wall extend between the top wall and the bottom wall, and 
   a bladder intermediate layer disposed between the bladder outer layer and the bladder first inner layer.   
     
     
         13 . The multilayered bladder system of  claim 12  wherein
 the bladder outer layer comprises an overlapping top wall. 
 
     
     
         14 . The multilayered bladder system of  claim 13  wherein
 the overlapping top wall comprises a partially overlapping top wall. 
 
     
     
         15 . The multilayered bladder system of  claim 12  wherein
 the bladder first inner layer comprises an overlapping top wall. 
 
     
     
         16 . The multilayered bladder system of  claim 15  wherein
 the overlapping top wall of the bladder first inner layer comprises a partially overlapping top wall. 
 
     
     
         17 . The multilayered bladder system of  claim 15  further comprising
 a layer of fiberglass provided within the overlapping top wall of the bladder first inner layer. 
 
     
     
         18 . The multilayered bladder system of  claim 12  further comprising
 a bladder second inner layer, the bladder second inner layer provided below the top wall of the bladder first inner layer. 
 
     
     
         19 . The multilayered bladder system of  claim 18  wherein
 the bladder first inner layer comprises an overlapping top wall, and 
 the bladder second inner layer is provided below the overlapping top wall of the first inner layer. 
 
     
     
         20 . The multilayered bladder system of  claim 18  wherein the bladder second inner layer comprises a flouroelastic rubber layer. 
     
     
         21 . The multilayered bladder system of  claim 12  further comprising
 a plurality of flouroelastic rubber layers provided between the top wall of the bladder first inner layer and the intermediate layer. 
 
     
     
         22 . The multilayered bladder system of  claim 12   further comprising a bladder second inner layer provided between the bladder first inner layer and the intermediate layer,   the bladder second inner layer extending along at least a portion of the first sidewall of the first inner layer.   
     
     
         23 . The multilayered bladder system of  claim 22  wherein
 the bladder second inner layer provided between the bladder first inner layer and the intermediate layer 
 extends along a portion of the second side wall of the bladder first inner layer. 
 
     
     
         24 . The multilayered bladder system of  claim 22  wherein
 the bladder second inner layer comprises flouroelastic rubber. 
 
     
     
         25 . The multilayered bladder system of  claim 12   wherein the top wall of the bladder outer layer comprises a first thickness and   the first side wall and the second side wall of the bladder outer layer comprises a second thickness,   wherein the first thickness of the top wall of the bladder outer layer is different than the second thickness of the first and second side walls of the bladder outer layer.   
     
     
         26 . A method of curing a charge, the method comprising the steps of
 placing a charge on a tool;   positioning a multilayered structure in a charge cavity defined by the charge placed on the tool;   laying up plies over the structure positioned in the charge cavity;   coupling the multilayered structure to a vent port;   covering the charge, the tool, the plies, and the multilayered structure with a vacuum bag over;   drawing a vacuum;   initiating a debulking process of the charge by inflating the multilayered structure;   finalizing debulk; and   curing the charge.   
     
     
         27 . A bladder system for use in curing a composite charge having an internal cavity, the bladder system comprising:
 a bladder comprising:
 a bladder bottom wall; 
 a first bladder side wall extending from the bottom wall; 
 a second bladder side wall extending from the bottom wall; and 
 a bladder top wall enclosing the bladder, 
 the bladder bottom wall, the first bladder side wall, the second bladder side wall, and the bladder top wall defining a bladder cavity, and 
   a flexible bladder support positioned within the bladder cavity, such that
 a first bearing surface of the flexible bladder support and a second bearing surface of the flexible bladder support 
 provide a compressive load support between a bottom surface of the bladder top wall and a top surface of the bladder bottom wall. 
   
     
     
         28 . The bladder system of  claim 27 ,
 wherein the flexible bladder support positioned within the bladder cavity,   further provides the compressive load support between an inner surface of the bladder first side wall and an inner surface of the bladder second side wall.   
     
     
         29 . The bladder system of  claim 27 , wherein
 the flexible bladder support comprises at least one corkscrew support.   
     
     
         30 . The bladder system of  claim 27 , wherein
 the flexible bladder support comprises a sinusoidal support.   
     
     
         31 . The bladder system of  claim 30  wherein the sinusoidal support comprises a constant width along a length of the sinusoidal support. 
     
     
         32 . The bladder system of  claim 30  further comprising:
 an additional support provided between the bladder top wall and the sinusoidal support. 
 
     
     
         33 . The bladder system of  claim 32  wherein:
 the additional support provided between the bladder top wall and the sinusoidal support comprises a rectangular support. 
 
     
     
         34 . The bladder system of  claim 30  wherein the sinusoidal support comprises a non-constant width. 
     
     
         35 . The bladder system of  claim 27  wherein
 the flexible bladder support comprises a segmented support. 
 
     
     
         36 . The bladder system of  claim 27  wherein
 the flexible bladder support comprises a double concave support. 
 
     
     
         37 . The bladder system of  claim 36  wherein
 the double concave support comprises: 
 a top bearing surface, 
 a bottom bearing surface, 
 a first side support, and 
 a second side support, 
 wherein the first side support extends in a concave manner from a first end of the bottom bearing surface to a first end of the top bearing surface, and 
 the second side support extends in a concave manner between a second end of the bottom bearing surface upwards towards a second end of the top bearing surface. 
 
     
     
         38 . The bladder system of  claim 27 , wherein
 the flexible bladder support extends along an entire length of the bladder.   
     
     
         39 . The bladder system of  claim 27 , wherein
 the bladder system comprises a plurality of wave features.   
     
     
         40 . The bladder system of  claim 27 , wherein
 the bladder system comprises a multilayered bladder system.   
     
     
         41 . The bladder system of  claim 27 , wherein
 the bladder system comprises a multi-segmented bladder system.   
     
     
         42 . A bladder system for use in curing a composite charge comprising an internal cavity, the bladder system comprising:
 a bladder comprising:
 a bladder bottom wall; 
 a first bladder side wall extending from the bottom wall; 
 a second bladder side wall extending from the bottom wall; and 
 a bladder top wall extending from a bladder front wall to a bladder back wall enclosing the bladder, 
 the bladder bottom wall, the first bladder side wall, the second bladder side wall, the bladder top wall, the bladder front wall, and the bladder back wall defining a bladder cavity, and 
   a flexible bladder support positioned within the bladder cavity, such that
 a first bearing surface of the flexible bladder support and a second bearing surface of the flexible bladder support 
 provide a compressive load support between a bottom surface of the bladder top wall and 
 an inner surface of the bladder first side wall and an inner surface of the bladder second side wall. 
   
     
     
         43 . The bladder system of  claim 42  wherein the flexible bladder support comprises a trapezoidal bladder support. 
     
     
         44 . The bladder support of  claim 42  wherein the bladder support comprises a segmented flexible bladder support. 
     
     
         45 . The bladder support of  claim 42  wherein the bladder support comprises
 a double concave support structure. 
 
     
     
         46 . The bladder support of  claim 45 , wherein the double concave support structure comprises:
 a top bearing surface,   a bottom bearing surface,   a first side support, and   a second side support,   wherein the first side support extends in a concave manner from a first end of the bottom bearing surface to a first end of the top bearing surface, and   the second side support extends in a concave manner between a second end of the bottom bearing surface upwards towards a second end of the top bearing surface.   
     
     
         47 . The bladder support of  claim 45  wherein the bladder support comprises a segmented bladder support. 
     
     
         48 . The bladder support of  claim 42  wherein the bladder support comprises a multi-segmented bladder support. 
     
     
         49 . A method of curing a charge, the method comprising the steps of
 placing a charge on a tool;   positioning a bladder in a charge cavity defined by the charge placed on the tool;   positioning a bladder support into a bladder cavity defined by the bladder;   laying up a plurality of plies over the structure and the bladder support;   providing a compressive load support by the bladder support;   coupling the bladder to a vent port;   covering the charge, the tool, the bladder support, and the bladder with a vacuum bag over;   drawing a vacuum;   initiating a debulking process of the charge by inflating the bladder;   finalizing debulk; and   curing the charge.