Patent Application
20210394463
The embodiments disclosed herein relate generally to process for forming composite aircraft components, i.e., aircraft components formed of a cured fiber-reinforced resin. According to specific embodiments, a finished surface of the composite aircraft component can be achieved by providing in-mold coating of the cured fiber-reinforced resin to thereby achieve a composite aircraft component having an exterior surface that does not necessarily require further finishing.
Composite materials formed of a cured fiber-reinforced resin material (e.g., cured carbon fiber reinforced epoxy) are well known in the fabrication of components for aircraft, e.g., flaps, ailerons, wing fuselage fairings, vertical and horizontal stabilizers, covers, interior parts and the like. Such components must however be painted in order to protect against the external environment, e.g., humidity, liquid leakage and the like.
One drawback to the use of composite materials is that they possess surface porosities due to the inherent nature of the conventional manufacturing processes. Aircraft components formed of a composite material must undergo pre-finish steps whereby a suitable filler material, e.g., pore filler, polyester filler or primer filler, is applied in order to correct surface defects and thereby obtain parts with the required smooth and aerodynamic surfaces. Such pre-finish steps will thereby necessarily increase production times and costs as well as expose operators to ergonomic issues since the filler material must be sanded to obtain the necessary surface quality for paint application.
It would therefore be highly desirable if composite aircraft components could be fabricated which avoid the pre-finish steps of the prior art processes. It is towards fulfilling such a need that the embodiments disclosed herein are directed.
Generally, the embodiments disclosed herein are directed toward a process whereby aircraft parts fabricated from a composite material (e.g., a cured fiber-reinforced resin material) may be subject to in-mold coating so that the cured component will exhibit the desired finished external surface when removed from the component mold.
According to specific embodiments, a process for making a composite aircraft component is provided whereby a contoured mold is provided so that a layer of a curable primer material may be applied onto an interior surface of the mold. The primer material is subsequently cured to form a cured layer of the primer material on the interior surface of the mold following which one or more prepreg layers of fiber reinforced uncured resin may be laid-up onto the cured primer layer to provide a component preform comprised of the mold having the cured layer of primer material and one or more prepreg layers thereon. The resulting preform may then be subjected to pressure and temperature conditions sufficient to cure the one or more prepreg layers and bond the prepreg layers to the cured layer of primer material and thereby form the composite aircraft component. Upon removal of the composite aircraft component from the mold, the cured layer of primer material will thereby form a finished surface of the composite aircraft component.
According to certain embodiments, the curable primer material (e.g., an epoxy paint) may be sprayed onto the interior surface of the mold. The prepreg layers may comprise reinforcement fibers selected from the group consisting of carbon, glass or aramid fibers impregnated with a curable resin, e.g., a curable epoxy resin.
These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.
The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which:
As is shown in
Once a suitable layer thickness (typically between about 60 μm to about 160 μm) of the primer material is applied onto the interior surface 14a of the mold 14, the mold can be cured according to step 20 (e.g., by placement in a curing oven) so as to cure the primer layer. The mold 14 containing a layer of the cured primer material (now designated as reference numeral 22) on the interior surface 14a of the mold 14 is depicted in accompanying
The cured layer 22 of primer material is maintained on the interior surface of the mold 14 so that operators can then apply in step 30 one or more layers or plies 24 of fiber-reinforced composite sheets. Such a lay-up procedure is schematically depicted in
The preform designated by reference numeral 42 in
While reference is made to a particular embodiment of the invention, various modifications within the skill of those in the art may be envisioned. Therefore, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof.
