TECHNOLOGY AREAS: Materials/Processes, Weapons

ACQUISITION PROGRAM: PMS 415 - Littoral Warfare Weapon, ACAT III

OBJECTIVE: Develop a low-permeability coating for nitrile rubber and nylon-reinforced nitrile rubber pressurized components. The coating must be pliable enough to conform to the shape of the nitrile rubber component as it expands/contracts due to fluctuations in differential pressure across the rubber. The coating must also withstand exposure to seawater for long periods (up to one year) and survive a minimum of 33 years.

DESCRIPTION: The TOMAHAWK Capsule Launching System (CLS) is being leveraged for integration of the Littoral Warfare Weapon (LWW) on SSGN and SSN 688I/Virginia Class Vertical Launch System capable platforms. The CLS includes a nylon-reinforced nitrile rubber fly-through cover. During stowage of the capsule in the submarine, the fly-through cover can be exposed to seawater. The fly-through cover must seal the capsule interior, which houses a missile, from the external environment. Since the nitrile rubber is permeable, and the humidity inside the capsule must be maintained below a specified threshold, a mylar-tin-mylar low permeability barrier must be installed over the nitrile rubber cover. These mylar-tin-mylar barriers are expensive, easily damaged, and present potential debris concerns after missile launch. A new low-permeability coating applied to the nitrile rubber would allow the fly-through cover to maintain the humidity within the capsule below required limits and eliminate the need for the mylar-tin-mylar barrier.

PHASE I: Identify an existing or develop a new coating for nitrile rubber that significantly decreases its permeability. Laboratory testing to demonstrate and quantify the permeability reduction will be required. Material testing to demonstrate the durability of the coating when the nitrile rubber is expanded/contracted and to quantify the amount of expansion that can be attained without damage to the coating will also be required.

PHASE II: Develop a process for applying the coating identified/developed during Phase I to the TOMAHAWK CLS nylon-reinforced nitrile rubber fly-through cover. Apply the coating to a small number of CLS fly-through covers. Conduct pressure cycling on the fly-through covers to demonstrate coating pliability and durability. Conduct permeability testing on the fly-through cover material with and without the coating to quantify the permeability reduction, both before and after pressure testing. Conduct testing of the coating to determine its longevity in a seawater environment.

PHASE III: Support integration of the developed coating into the TOMAHAWK CLS fly-through cover development for Littoral Warfare Weapon application. This coating, upon meeting Navy requirements, could also be transitioned into various other programs (i.e.: encapsulated UAVs) that require nitrile rubber membranes with low permeability.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: The low permeability coating would be available for numerous commercial applications for which nitrile rubber (and potentially other elastomers) are not currently suitable due to their permeability. Examples include packaging materials and pressure vessels.

REFERENCES:
1. Joint Cruise Missiles Project, Capsule Closure Assembly, Rev H, Drawing No. JCM-14051

KEYWORDS: Low permeability; Coating; Pliable; Nitrile rubber; Nylon; Fly-through cover

TPOC: James Coleman
Phone: (401)832-1795
Fax:
Email: [email protected]
2nd TPOC: W. Donald Hornbeck
Phone: (401)832-7899
Fax:
Email: [email protected]

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between November 13 and December 9, 2007, you may talk directly with the Topic Author(s) to ask technical questions about the topics. Their contact information is listed above. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting December 10, 2007, when DoD begins accepting proposals for this solicitation.

However, proposers may still submit written questions about solicitation topics through the DoD's SBIR/STTR Interactive Topic Information System (SITIS), in which the questioner and respondent remain anonymous and all questions and answers are posted electronically for general viewing until the solicitation closes. All proposers are advised to monitor SITIS (08.1 Q&A) during the solicitation period for questions and answers, and other significant information, relevant to the SBIR 08.1 topic under which they are proposing.

If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (866) 724-7457 or email weblink.