Preimidized Powder Towpregs for Low Cost, High Performance Missile Cases

The Missile Defense Agency (MDA) is soliciting proposals for new missile materials to expand the capability of current air-to-ground missile systems. This expansion of capability dictates the development of lighter weight materials that are capable of short duration exposures to temperatures as high as 800°F. A novel approach to filament winding using high-temperature matrix materials is proposed. This approach uses preimidized polyimide powder impregnated tows (“powder towpreg”) incorporating carbon nano-fibers as the direct feed for a filament winding process. While powder towpreg is not new, the use of preimidized powder and non-autoclave processing with incorporated nano-material in the matrix is. By using preimidized powder to shorten cure cycles and non-autoclave cure, considerable cost savings can be realized. The incorporation of nano-fiber reinforcement in the matrix should lead to improved properties that result in lighter weight parts as well. These 100% solids materials better use the expensive high-temperature polyimide resins (low resin loss), provide better uniformity of the matrix resin throughout fabricated parts, reduce cure cycle times due to preimidization, and should provide superior mechanical properties in the final components. As such, this approach has the potential for reducing costs of future aircraft and spacecraft structures and propulsion systems by a variety of means.