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Self-Actuating Seals for Barrier-Fabric Protective Coveralls
Navy SBIR 2011.2 - Topic N112-106 NAVAIR - Ms. Donna Moore - [email protected] Opens: May 26, 2011 - Closes: June 29, 2011 N112-106 TITLE: Self-Actuating Seals for Barrier-Fabric Protective Coveralls TECHNOLOGY AREAS: Human Systems ACQUISITION PROGRAM: SaaS Air Soldier, Layered Clothing Ensemble, ACAT II (US Army) RESTRICTION ON PERFORMANCE BY FOREIGN CITIZENS (i.e., those holding non-U.S. Passports): This topic is "ITAR Restricted." The information and materials provided pursuant to or resulting from this topic are restricted under the International Traffic in Arms Regulations (ITAR), 22 CFR Parts 120 - 130, which control the export of defense-related material and services, including the export of sensitive technical data. Foreign Citizens may perform work under an award resulting from this topic only if they hold the "Permanent Resident Card", or are designated as "Protected Individuals" as defined by 8 U.S.C. 1324b(a)(3). If a proposal for this topic contains participation by a foreign citizen who is not in one of the above two categories, the proposal will be rejected. OBJECTIVE: Develop an innovative garment seal design or material that will allow nonconstricted fit and air exchange during routine ambient conditions yet will self-actuate upon immersion to exclude the influx of cold water. DESCRIPTION: Current world operations expose our military to some of the deadliest environmental threats ever encountered in war: biological agents, chemical weapons, contaminated conditions, frigid seas, severe winds, and equatorial heat. Protective coveralls consisting of a barrier fabric with seals at the neck, wrists, and sometimes ankles are worn by our warfighters to repel these threats. There have been many advances in the technology of barrier fabrics, coatings, and laminates; yet, for the last 40 years or more, the seals have been (and still are) made of a constrictive rubber such as neoprene, latex, or butyl. Although these rubber materials are very effective at sealing out threats, they also seal in body heat, compress soft tissues to the point of impairment and/or pain, and impede blood flow. One example of a barrier coverall with constrictive rubber seals (latex) is the U.S. Navy�s CWU-86/P anti-exposure suit (and used by U.S. Army aviators), which is worn constantly during flight as a contingency against immersion hypothermia as a consequence of ditching or ejection in cold water. Numerous Fleet hazard reports have documented the cost of this constant-wear suit to the wearer�s endurance. Because the seals are air/water tight and no auxiliary air exchange is provided, for example, the body heat buildup in the suit is considerable. Operators avoid wearing (or frankly refuse to wear) the suit for flights that traverse wide temperature conditions (e.g., hot desert to high-altitude mountain; hot ambient air over cold water, as in most north Pacific operations) even though wear is required by instruction. The neck seal is frequently reported as constricting blood flow to the hands, causing loss of dexterity and touch perception, and pressing the vocal chords against the windpipe, causing unintelligible speech as well as discomfort. Consequently, the failure rate of the seals is high, sometimes tearing during dressing, and sometimes creatively (and stealthily) modified by the wearer to allow blood flow, ventilation, and intelligible speech during preflight and in-flight. Total ownership costs are high as the spare part itself is not repairable, and replacement involves tedious maintenance and inspection. The Navy has long recognized these deficiencies; previous Navy and industry improvement efforts have included inflatable toroids, absorbent gel wraps, drawstrings, ratcheting ring clamps, baffles, and full head/neck hoods with see-through face enclosures. None, however, have been as effective or supportable as the necessarily tight and constricting latex and neoprene seals. The goal of this topic is to develop an innovative, affordable, and supportable seal design or material that will allow nonconstricted fit and air exchange during routine ambient conditions yet will self-actuate upon immersion to exclude the influx of cold water. Specific requirements are to (a) limit influx of no more than 118 milliliter (ml) (1/2 C) water upon 30-foot (ft) immersion in turbulent 32 degrees Fahrenheit in surface salinities representative of seawater (32-35 parts per thousand (ppt)) and open baywater (10-17 ppt); (b) exclude water for 12 hours immersion with the neck area submerged in conditions of (a); (c) remain operable (a) and (b) after six months of operational wettings (e.g., rain, sweat, seaspray, leakage inspections); (d) allow air exchange through the neck opening in dry-suit applicable ambient cockpit conditions; (e) provide equivalent flame resistance to current materials; (f) remain nontoxic to skin; (g) resist mission and environmental contaminants (e.g., sand, petroleum, oil, lubricants, solar radiation, temperature extremes of negative 20 degrees Fahrenheit to positive 140 degrees Fahrenheit, mold, mildew, salt water; (h) install into the current dry suit; (i) tolerate multiple donning actions over bare head; (j) accommodate the head/neck dimensions of the central 95 percent of Navy flying population; (k) be compatible with the current Navy gear and equipment required to be worn with neck seals, such as flotation collars, coverall collars, mask, and helmets; (l) yield a service life of 2 years; (m) have a shelf life of 5 years; and (n) be maintainable by intermediate-level Navy personnel and support equipment. PHASE I: Demonstrate a conceptual design of the garment seal. Verify that the concept can meet the stated requirements through analysis and limited laboratory demonstrations. Provide cost and reliability estimates. PHASE II: Validate an operational prototype by demonstration on human subjects in controlled immersions. Demonstrate compliance with requirements. Provide a technical drawing and cost and reliability estimates. PHASE III: Develop mass production for sustainment by defense supply and commercialization for the private sector. On average, defense procurement is 8,000 units per year. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: This seal material could benefit other military, industrial, and recreational dry suits as well as industrial and recreational weather-protective garments. Depending on the actuating mechanism, the seal could be adapted for use with medical compression bandages, chemical biological protective coveralls, geotextiles, filtration mechanisms, and industrial gaskets. REFERENCES: 2. Hayes, A. W. (Ed.). (2001). Principles and methods of toxicology (4th ed., pp 403-407). Philadelphia, PA: Taylor Francis. 3. Department of Defense. (2008). Environmental engineering considerations and laboratory tests (MIL-STD-810G). Aberdeen, MD: Department of the Army, Developmental Test Command. 4. Gordon, C. C., Foti, H. M., Donelson, S. M., & Naval Air Warfare Center Aircraft Division. (1997). 1995 U.S. Navy/Marine Corps matched male and female anthropometric eligible pilot databases (ADA327479). Patuxent River, MD: Naval Air Warfare Center Aircraft Division. Retrieved from http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA327479&Location=U2&doc=GetTRDoc.pdf 6. American Society of Automotive Engineers. (2009). Engineering drawing practices (ASME Y14.100-2004). New York, NY: Author. KEYWORDS: seals; garments; gaskets; immersion; biological; actuating
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