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.

Abstract: The object of the invention is a process for the production of a reinforced acoustically resistive layer, in which there is produced a layer of structural reinforcement from fibers pre-impregnated with a thermosetting or thermoplastic resin, said layer having a given quantity of open surface relative to the acoustic waves to be handled, there is associated with said reinforcing layer a metallic acoustic cloth whose mesh is suitable for the quantity of open surface of said structural layer, and the polymerization or consolidation of said resins under pressure and temperature suitable for the resins used, is carried out, characterized in that there is associated with the impregnation resin for the fibers a component (2a) adapted for macromolecular interpenetration with said resin during the polymerization or consolidation so as to ensure for the reinforcing layer (2) improved mechanical and adhesive properties for the metallic cloth. Application to the production of acoustic panels.

Abstract: A process for the production of a panel with a protective acoustic damping layer. The protective layer includes at least one porous core covered, on the one side, with a porous acoustic damping layer and on the other side with a total acoustic reflector. The porous damping layer is emplaced by striping or draping. The porous damping layer consists of parallel strips. Edges of the strips of the porous damping layer are positioned facing a strip deposited by striping or draping and containing a thermoplastic, thermosetting or thermofusible material adapted, by subsequent heating, to ensure the securement of the edges of said strips of the porous damping layer with the adjacent strip of thermoplastic, thermosetting or thermofusible material.

Abstract: Tooling for molding with keys for the production of air intakes without clips of substantially tubular shape, comprises a self-supporting mandrel with keys comprising at least three sectors in the form of panels, namely at least two articulated sectors (3) retractable toward the center of the mandrel and a key sector independent from the other sectors and insertable between these latter, thereby, by abutment, to define, by their external surfaces, a continuous surface corresponding to the internal surface of the air intake, elements to lock in abutted position the sectors, and a control device, disconnectable from the mandrel, of the relative displacement of the movable sectors to place them either in a molding position by abutment of the sectors, or in an unmolding position by retraction of the sectors toward the interior of the mandrel.

Abstract: A process is described for the production of holes, particularly of micro-perforations, in a composite material, constituted by fibers embedded in a resinous matrix, characterized in that it consists in a preliminary step of carrying out on a specimen of the composite material, with the help of a laser beam, tests consisting in adjusting the duration of illumination at a predetermined place on the specimen, as well as the focusing and power of said laser beam, so as to confine the temperature in the mass of the material to a range of temperatures both greater than the thermal decomposition temperature of the matrix resin and below the temperature of altering the physical properties of the fibers, so as to carry out the elimination of the resin without affecting the physical integrity of the fibers, then in reproducing on the material (8) to be treated, at each position of a perforation to be made, the operating conditions of the laser (10, 12) so as to constitute in said material a through passage, as a resul

Abstract: A process for the production of a panel with a protective acoustic damping layer. The protective layer includes at least one porous core covered, on the one side, with a porous acoustic damping layer and on the other side with a total acoustic reflector. The porous damping layer is emplaced by striping or draping. The porous damping layer consists of parallel strips. Edges of the strips of the porous damping layer are positioned facing a strip deposited by striping or draping and containing a thermoplastic, thermosetting or thermofusible material adapted, by subsequent heating, to ensure the securement of the edges of said strips of the porous damping layer with the adjacent strip of thermoplastic, thermosetting or thermofusible material.

Abstract: A multi-component acoustically resistive layer, for acoustical attenuating panels having a cellular core (1) flanked, on the sound wave arrival side, with an acoustically damping layer (2) and, on the opposite side, with a rear reflector (3), comprises a first structural component (4) in contact with the aerodynamic flow and formed by at least one layer of fibers connected by a suitable resin and oriented in the direction of aerodynamic flow the component (4) comprising a suitable quantity of open surface; a dissipating component (6) disposed against the surface of the first component (4) opposite the flow, formed by a metallic cloth; and a second structural component (7) formed by at least one layer of fibers connected by a suitable resin, oriented orthogonally to the direction of aerodynamic flow. The second structural component (7) is connected to the cellular core (1) and comprises a suitable open surface quantity.

Abstract: A process for the production of a panel with a protective acoustic damping layer. The protective layer includes at least one porous core covered, on the one side, with a porous acoustic damping layer and on the other side with an acoustic reflector. The porous damping layer is emplaced by striping or draping. The porous damping layer consists of parallel strips. Edges of the strips of the porous damping layer are positioned facing a strip deposited by striping or draping and containing a thermoplastic, thermosetting or thermofusible material adapted, by subsequent heating, to ensure the securement of the edges of said strips of the porous damping layer with the adjacent strip of thermoplastic, thermosetting or thermofusible material.

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.

Abstract: A process for the production of a panel (7) of composite material with stiffening strips (3), in which a mold (1) 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 the first ply (2) is covered with at least one second ply (4) of fibers pre-impregnated with resin, then a bladder (6) 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 (3) 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 (3) and one and/or the other of the plies (2, 4).

Abstract: Tooling for molding with keys for the production of air intakes without clips of substantially tubular shape, comprises a self-supporting mandrel with keys comprising at least three sectors in the form of panels, namely at least two articulated sectors (3) retractable toward the center of the mandrel and a key sector independent from the other sectors and insertable between these latter, thereby, by abutment, to define, by their external surfaces, a continuous surface corresponding to the internal surface of the air intake, elements to lock in abutted position the sectors, and a control device, disconnectable from the mandrel, of the relative displacement of the movable sectors to place them either in a molding position by abutment of the sectors, or in an unmolding position by retraction of the sectors toward the interior of the mandrel.

Abstract: A multi-component acoustically resistive layer, for acoustical attenuating panels having a cellular core (1) flanked, on the sound wave arrival side, with an acoustically damping layer (2) and, on the opposite side, with a rear reflector (3), comprises a first structural component (4) in contact with the aerodynamic flow and formed by at least one layer of fibers connected by a suitable resin and oriented in the direction of aerodynamic flow the component (4) comprising a suitable quantity of open surface; a dissipating component (6) disposed against the surface of the first component (4) opposite the flow, formed by a metallic cloth; and a second structural component (7) formed by at least one layer of fibers connected by a suitable resin, oriented orthogonally to the direction of aerodynamic flow. The second structural component (7) is connected to the cellular core (1) and comprises a suitable open surface quantity.

Abstract: The object of the invention is a process for the production of holes, particularly of micro-perforations, in a composite material, constituted by fibers embedded in a resinous matrix, characterized in that it consists in a preliminary step of carrying out on a specimen of the composite material, with the help of a laser beam, tests consisting in adjusting the duration of illumination at a predetermined place on the specimen, as well as the focusing and power of said laser beam, so as to confine the temperature in the mass of the material to a range of temperatures both greater than the thermal decomposition temperature of the matrix resin and below the temperature of altering the physical properties of the fibers, so as to carry out the elimination of the resin without affecting the physical integrity of the fibers, then in reproducing on the material (8) to be treated, at each position of a perforation to be made, the operating conditions of the laser (10, 12) so as to constitute in said material a through p

Abstract: The object of the invention is a process for the production of a reinforced acoustically resistive layer, in which there is produced a layer of structural reinforcement (2) from fibers pre-impregnated with a thermosetting or thermoplastic resin, said layer having a given quantity of open surface relative to the acoustic waves to be handled, there is associated with said reinforcing layer (2) a metallic acoustic cloth (5) whose mesh is suitable for the quantity of open surface of said structural layer, and the polymerization or consolidation of said resins under pressure and temperature suitable for the resins used, is carried out, characterized in that there is associated with the impregnation resin for the fibers a component (2a) adapted for macromolecular interpenetration with said resin during the polymerization or consolidation so as to ensure for the reinforcing layer (2) improved mechanical and adhesive properties for the metallic cloth (5).

Abstract: The object of the invention is a process for the production of a panel with a protective acoustic damping layer, comprising at least one porous core covered, on the one side, with a porous acoustic damping layer (10) and on the other side with a total acoustic reflector, in which at least one said porous layer (10) is emplaced by striping or draping, said porous layer (10) being constituted of parallel strips (13), characterized in that the edges (15) of the strips (13) of the porous layer (10) are positioned facing a strip (16) deposited by striping or draping and containing a thermoplastic, thermosetting or thermofusible material adapted, by subsequent heating, to ensure the securement of the edges of said strips (13) with the adjacent strip (16).

Abstract: The object of the invention is a process for the production of a panel (7) of composite material with stiffening strips (3), in which a mold (1) 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 placed to cover the above elements, a suitable vacuum is established in the space between the mold (1) and the bladder (6), the assembly is then placed in an autoclave to subject it to a pre-established polymerization cycle for the resin, at temperatures and pressures suitable for said resin, and finally the panel is demolded, characterized in that before said emplacement of the stiffening strip (3) and/or of the second ply (4), there is interposed at least one layer, film or the like (5) of a non-