High pressure molding of composite parts
View Patent ↗Composite pre-forms are molded at high pressure to form composite parts that can be used in place of metal-based high performance parts, such as the outlet guide vanes found in turbofan jet engines. The composite pre-forms include two different fiber orientations that are co-molded in a resin matrix at high pressures to provide composite outlet guide vanes and other high performance parts. Chambers within the composite part are optionally formed during molding of the pre-form at high pressures.
1. A moldable structure comprising:
a moldable body comprising:
a central portion comprising unidirectional fiber reinforcement and an uncured thermosetting resin that has a curing temperature at which said uncured thermosetting resin is converted from a moldable resin to a solid resin having a glass transition temperature that is above said curing temperature, said central portion comprising an internal surface that defines a chamber located within said central portion;
solid end portions located at each end of said central portion, said end portions comprising randomly oriented segments of unidirectional fiber tape; and
a solid mandrel located within said chamber, said solid mandrel being in contact with said internal surface to provide shape thereto, said solid mandrel comprising a material having a melting point at which said solid mandrel material melts to form a liquid material that can be drained out through a hole in said internal surface, said melting point being above said curing temperature and below said glass transition temperature.
2. A moldable structure according to claim 1 wherein the curing temperature of said uncured thermosetting resin is between 170° C. and 225° C.
3. A composite part comprising a moldable structure according to claim 1 that has been molded to form said composite part and wherein said solid mandrel has been melted to form said liquid and wherein said liquid material has been drained from said chamber.
4. A moldable structure according to claim 2 wherein said solid mandrel material comprises a eutectic metal alloy.
5. A moldable structure according to claim 1 wherein said moldable structure is in the shape of an outlet guide vane.
6. A composite part according to claim 3 wherein said composite part is an outlet guide vane.
7. A moldable structure according to claim 4 wherein said eutectic metal alloy comprises tin and zinc or bismuth.
8. A moldable structure according to claim 7 wherein said eutectic metal allow is composed of 91 weight percent tin and 9 weight percent zinc.