SBIR-STTR Award

There is a navy requirement for stronger and lighter weight ASW sonobuoy cables. The purpose of this study is to evaluate the use of high strength polyethylene materirals spectra 900 and spectra 1000 as the strength member of the cables in order to achieve that goal. The benchmark cable for this study will be constructed as described in the solicitation (details described in report no. Nadc-74221-20, "investigation of kelvar fiber cables for use in ASW sonobuoys" by j. Brett and r. Hollerx dated January 20^ 1975). This study will evaluate the physical properties of spectra 900 and 1000 for their application to sonobuoy cables and maximize the textile yarn properties such as tenacity total deniert filament denier twist elongation and modulus. Our study will also investigate the proper processing conditions such as twister spindle speed and ring traveler materials which if not correct will damage yarn and reduce strength. The second part will produce various braided and served candidates from each material varying the construction parameters such as type of braid, number of carriers yarn denier denier per -scarrier braid angle number of ends denier of ends and lay angle ^-to select the final candidates for cable design and construction. These final designs will address the two naval requirements: 1) cables of greater strength with equal diameter; and 2) calbes of equal strength with smaller diameter. The electrical integrity of the cable will be tested and maintained.

During Phase II we will be continuing our work to improve on the baseline kevlar cable constructions. This will include working with the original 375 and 650 denier spectra 1000 and the new 185 denier spectra 1000. We will limit our work to braided constructions and spectra 1000 material. In addition we would propose producing parallel constructions of kevlar material produced on the same equipment with the same manufacturing techniques to achieve direct comparison of materials. Experimentation with bonding of spectra and termination of spectra will also be addressed. Present techniques and methods of terminology may not be adequate to make spectra cable a viable option. Some progress in this area has been made, but additional research is required.