2.1 Select and procure materials

Selecting the fibers for inclusion in this test matrix was relatively easy. The fibers needed to represent current state of the art for filament wound composite pressure vessels for high performance applications. The Zylon™ fiber (high strength variant) was of interest due to its demonstrated high performance in pressure vessel applications, its demonstrated toughness (with regards to impact resistance), and its previously demonstrated affinity for an experimental NASA resin of interest. HEI had seen excellent delivered fiber strength for this combination. The selection of a high performance carbon fiber was also quite easy because the Toray T-1000 12k is the material of choice for many high performance pressure vessel applications. Sufficient quantities of each fiber were procured.

The selection of resin was not quite as straight forward. There are numerous resin systems with demonstrated performance at ambient conditions that were worthy of consideration. In the end HEI decided to select a typical pre-preg resin system, a common wet wound resin system, and the experimental NASA system (mentioned above). HEI originally intended to use the TCR-UF3339-95 resin system on both carbon and zylon fibers. This is a somewhat "toughened" resin system and thought to have properties more suitable to very cold conditions. HEI procured some Zylon fiber impregnated with this system but the current extreme shortage of Toray T-1000 fiber precluded getting any of that fiber impregnated with that system. HEI was able to obtain T-1000 with a very similar TCR system, the UF3325-95. HEI had previously purchased sufficient dry fiber of both the T-1000 and Zylon to enable fabrication of sufficient cylinders using the two wet winding resins of choice, an Epon 828 system and the NASA experimental system (also referred to as Cryo A & B).

M30S fiber prepregged with UF3339-100 resin was also selected to be included in testing. M30S is more of a mid-grade fiber and it was desired to expand the cryogenic database on a more commercial grade fiber.

HEI also included a smaller population of cylinders built by Dr. Thomas DeLay of NASA made with IM9 (977-6 resin), IM7 (977-2 resin), T-1000 (977-6 resin), and TRH50 (WDE-3D-1 resin) fibers.

Previous 1.0 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 4.0 5.0 Appendix Next

HyPerComp Engineering, Inc.; SBIR NAS8-03027 Final Report