Process for the production of a panel of composite material with stiffening strips and panel thus obtained

• US 7,790,082 B2
• Filed: 04/30/2004
• Issued: 09/07/2010
• Est. Priority Date: 05/05/2000
• Status: Expired due to Fees

• Current Assignee: Airbus Operations SAS (Airbus SE)
• Original Assignee: Airbus France
• Inventors: Buge, Michel, Legeay, Bruno, Rambaud, Eric, Porte, Alain
• Primary Examiner(s): Huson; Monica A
• Application Number:
  US10/834,833
• Publication Number:
  US 20040227276A1
• Time in Patent Office: 2,321 Days
• Field of Search: 264510-511, 264257-258, 264316-317, 264/324, 264/334, 264/336
• US Class Current: 264/258
• CPC Class Codes: B29C 37/0075 using release sheets
• CPC Class Codes: B29C 70/086 and with one or more layers of pure plastics material, e.g. foam layers applying a non-preformed coating, e.g. a gel-coat, B29C37/0025; with foam blocks B29C70/86
• CPC Class Codes: B29C 70/342 using isostatic pressure
• CPC Class Codes: B29C 70/54 Component parts, details or accessories; Auxiliary operations , e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
• CPC Class Codes: B29D 99/0014 provided with ridges or ribs, e.g. joined ribs

Abstract

A process for the production of a panel of composite material with stiffening strips, in which a mold is draped with at least one first ply of fibers pre-impregnated with resin, there is emplaced at desired positions on said ply at least one stiffening strip, the stiffening strip as well as at least a portion of the remaining surface of the first ply is covered with at least one second ply of fibers pre-impregnated with resin, then a bladder is placed to cover the above elements, the assembly is then placed under vacuum and then in an autoclave to polymerize the resin. Before emplacement of the stiffening strip and/or of the second ply (4), there is interposed at least one layer (5) of a non-adherent material between at least one portion of the surface of the stiffening strip and one and/or the other of the plies.

Claims

1. In a process for the production of a panel (7) of composite material with stiffening strips (3), in which a mold (1) having the shape and size of the panel to be produced, is draped with at least one first ply (2) of fibers pre-impregnated with resin, there is emplaced at desired positions on said ply (2) at least one stiffening strip (3), the stiffening strip (3) as well as at least a portion of the remaining surface of said first ply (2) is covered with at least one second ply (4) of fibers pre-impregnated with resin, then a bladder (6) is positioned to cover the above elements, a suitable vacuum is drawn in the space between the mold (1) and the bladder (6), the assembly is then disposed in an autoclave to subject it to a pre-established polymerization cycle for the resin, at temperatures and pressures suitable to said resin, and finally, the panel is demolded;

the stiffening strip (3) being a foam structure, and prior to said emplacement of the stiffening strip (3) and/or of the second ply (4), there is interposed at least one layer (5) of a non-adherent material between at least a portion of the surface of the stiffening strip (3) and one and/or the other of said plies (2, 4) for avoiding sinking of said fibers into said stiffening strips and wherein said foam structure is retained permanently within the panel after the resin is polymerized.

2. Process according to claim 1, characterized in that each stiffening strip (3) is totally enclosed by at least one layer (5) of non-adherent material.

3. Process according to claim 1, characterized in that the layer of composite material constituted by said first ply or plies of pre-impregnated fibers, is subjected to curing before emplacement of said stiffening strips (3), layer (5) of non-adherent material and second ply or plies.

4. Process according to claim 1, characterized in that the non-adherent material (5) is selected from the group consisting of Teflon and compounds of the silicone family.

5. Process according to claim 1, characterized in that between the mold (1) and said first ply (2) there is interposed a surfacing film.

6. Process according to claim 1, characterized in that the non-adherent material (5) is selected from the group consisting of Teflon and compounds of the silicone family.

7. In a process for the production of a panel (7) of composite material with stiffening strips (3), in which a mold (1) having the shape and size of the panel to be produced, is draped with at least one first ply (2) of fibers pre-impregnated with resin, there is emplaced at desired positions on said ply (2) at least one stiffening strip (3), the stiffening strip (3) as well as at least a portion of the remaining surface of said first ply (2) is covered with at least one second ply (4) of fibers pre-impregnated with resin, then a bladder (6) is positioned to cover the above elements, a suitable vacuum is drawn in the space between the mold (1) and the bladder (6), the assembly is then disposed in an autoclave to subject it to a pre-established polymerization cycle for the resin, at temperatures and pressures suitable to said resin, and finally, the panel is demolded;

the stiffening strip (3) being a cellular structure or foam structure, and the plies (2, 4) completely surround the stiffening strip (3), and prior to said emplacement of the stiffening strip (3) and/or of the second ply (4), there is interposed at least one layer (5) of a non-adherent material between at least a portion of the surface of the stiffening strip (3) and one and/or the other of said plies (2, 4) for avoiding sinking of said fibers into said stiffening strips and wherein said stiffening strips are retained permanently within the panel after the resin is polymerized.

8. Process according to claim 7, characterized in that each stiffening strip (3) is totally enclosed by at least one layer (5) of non-adherent material.

9. Process according to claim 7, characterized in that the layer of composite material constituted by said first ply or plies of pre-impregnated fibers, is subjected to curing before emplacement of said stiffening strips (3), layer (5) of non-adherent material and second ply or plies.

10. Process according to claim 7, characterized in that the non-adherent material (5) is selected from the group consisting of Teflon and compounds of the silicone family.

11. Process according to claim 7, characterized in that between the mold (1) and said first ply (2) there is interposed a surfacing film.

12. Process according to claim 8, characterized in that the layer of composite material constituted by said first ply or plies of pre-impregnated fibers, is subjected to curing before emplacement of said stiffening strips (3), layer (5) of non-adherent material and second ply or plies.

13. Process according to claim 12, characterized in that the non-adherent material (5) is selected from the group consisting of Teflon and compounds of the silicone family.