Method of making a composite fibre component with thermoplastic stiffening elements
View Patent ↗The invention relates to a method for producing a composite component reinforced by stiffening elements. Composite component is produced by the inside gluing of a monolithic component to a multiplicity of stiffening elements by means of an adhesive suitable for this particular application. Stiffening elements are formed with a fiber reinforced, amorphous thermoplastic material. Monolithic component of composite component consists of a fiber reinforced duroplastic material—for example a composite epoxy matrix—in which are embedded, for reinforcement, carbon fibers, basalt fibers, natural fibers, ceramic fibers, Aramide® fibers, Kevlar® fibers or any combination thereof. Monolithic component is glued to thermoplastic stiffening elements by an adhesive under the influence of pressure and temperature. Here a tolerance compensation is carried out essentially by stiffening elements, if necessary being plastically deformed, so that high dimensional stability is achieved. Composite components, which can be subject to high mechanical loads, are therefore provided, in particular, as spare or replacement parts for outer lining parts on aircraft. The invention also relates to a composite component produced by means of a method according to the invention.
1. A method for producing a composite component reinforced with a multiplicity of stiffening elements, wherein the stiffening elements are formed with a fibre reinforced, gluable thermoplastic material, comprising the following steps:
producing a fully cured monolithic component having a fibre reinforced duroplastic material;
producing thermoplastic stiffening elements;
providing an inner tool, wherein the inner tool is a single piece and comprises at least in one region a multiplicity of rib-type recesses or beads which are adapted to receive the stiffening elements, wherein a cross-sectional geometry of the rib-type recesses or beads corresponds to a cross-sectional geometry of the stiffening elements to be inserted, and wherein surface geometry of an outer surface of the inner tool predetermines the inner theoretical geometry of the composite component to be produced;
providing an outer tool, wherein the outer tool is adapted to receive the fully cured monolithic component and wherein the outer tool comprises an inner surface which forms an outer surface of the monolithic component;
inserting the stiffening elements in the corresponding recesses of the inner tool;
placing the fully cured monolithic component on the inner tool;
inserting the fully cured monolithic component in the outer tool to increase pressing pressure and dimensional stability; and
gluing the thermoplastic stiffening elements to the fully cured monolithic component with an adhesive;
wherein the inner tool and/or the outer tool are heated to a temperature of between 125° C. to 225° C. to cure the adhesive,
wherein the inner tool and the outer tool are loaded with pressure when the inner tool and the outer tool are pressed against each other during gluing of the stiffening elements, and
wherein a tolerance compensation takes place between the stiffening elements and the shape-defining fully cured monolithic component.
2. The method according to claim 1 , wherein rib-type stiffening profiles which have an essentially trapezoidal cross-sectional geometry are glued to the fully cured monolithic component as stiffening elements in the region of a joining surface.
3. The method according to claim 1 , wherein an adhesive film, an adhesive strip, and adhesive tape, a pasty adhesive, or an adhesive with a low viscous consistency is used as adhesive for gluing the stiffening elements to the fully cured monolithic component having a carbon fibre reinforced epoxy resin.
4. The method according to claim 1 , wherein the adhesive is an adhesive film, a glue, an adhesive tape, a double adhesive tape, a prepreg material, an adhesive strip, a pasty adhesive or an adhesive with a low viscous consistency.