High Pressure Resistant, Non-Powered, Flexible Chemical/Biological Protective Closure System

Description:

TECHNOLOGY AREA(S): Chemical/Biological Defense

OBJECTIVE: The overall objective is to develop a flexible Chemical/Biological (CB) resistant closure system that does not leak liquid (goal of a 36 PSI dynamic load) (2), (3), (4) or air (goal of a 16 PSI static load) (2), (3), (4). This closure system will maintain an air tight seal while subjected to both positive and negative pressures on either side of the seal while providing a low life cycle cost (goal of less than $15 per foot).

DESCRIPTION: Improvements in closures and interfaces are needed to provide liquid, vapor and aerosol CB protection while meeting the strenuous mechanical demands encountered while fielded in COLPRO shelters and body bags that experience pressure differentials. A need currently exists to develop a vapor tight closure that can withstand pressures experienced during normal military air transportation methods(2), (3), (4) to include withstanding stresses experienced in the rapid loss of cabin pressure. The closure system should also be resistant to CB agents, able to be decontaminated by normal military decontamination techniques (bleach, HTH), operated with gloves by the 5% percentile female to the 95% male(6), not require power to operate and have the ability to be used in austere (UV, sand, wind, hot, cold, etc) environments (1). Ideally this closure system would be reusable (able to be opened and closed multiple times). This closure could be used in collective protection systems, inflatable structures, vestibule attachments, individual protection garments, packaging of human remains and air transportation of sick individuals. All materials must comply with Berry Amendment requirements (5). Current closures that are marketed as “air tight” will leak air when under pressure and/or are made of materials that are known to not be resistant to C/B agents. Current solutions are generally based on one of three technologies (or in some cases in a combination of several approaches). These systems suffer from several significant deficiencies that limit the overall utility of the collective protection system into which they are integrated: • zippers: • not decontaminable • not durable • low tolerance to structural load at useable sizes • no standardization • requires secondary closure at end of track • excessive air leakage • difficult to clean and keep serviceable • sewn to liner which creates further leak points • hook and pile/loop:• not decontaminable • not durable • excessive air leakage • edge alignment (therefore engagement area) at mercy of operator • difficult to clean and keep serviceable • joint weakens with use • sewn to base material which creates further leak points • zip-track: • tracks stretch and deform • difficult to use in field conditions • requires secondary closure at end of track • no standardization • takes permanent crease in storage • leaks water at deformations • difficult to install to liner Technical Goals: While the CB seals must be continuous, easy to use, and able to withstand heavy use, they must also provide the mechanical strength necessary to withstand continuous loading from the internal overpressure used with collective protection shelters. A comprehensive performance specification has not been completed, but in general the required system performance can be summarized as follows: • not leak liquid (goal of a 36 PSI dynamic load) (2), (3), (4) or air (goal of a 16 PSI static load) (2), (3), (4). • resist expected field stresses (fabric loads, twisting, pulling, etc.) • ease of use in all operational scenarios (cold/wet, night, masked/gloved, etc.) • chemical resistant to included decontamination fluids • easily attached to base material • low life cycle cost, technical maturity, high field utility (ruggedness, etc), allows small radius curves (for corners of floor/wall etc), no support equipment required to maintain seal • no support equipment required to maintain seal (electrical power, compressed air, etc.) • minimal impact on storage volume

PHASE I: Design a concept for the high pressure resistant closure mechanism. Develop a test plan to evaluate the closure performance. Demonstrate how the proposed technology will meet the requirements. This can be done by technology demonstration, scale prototype or CAD. Demonstrate that the chosen materials are CB resistant. This can be done by white paper or by providing previous test results (7). Phase I deliverables will include monthly reports, a final report (including a cost feasibility study), and a draft test plan.

PHASE II: Optimization of concept from Phase I. Produce and test multiple iterations of design concept. Validate closure test plan. Demonstrate the chosen materials will perform in operationally relevant environments. Phase II deliverables at the end of year 1 will include monthly reports, a 6-8 foot long prototype, and a test report documenting closure performance in a lab setting. Phase II deliverables at the end of year 2 will include monthly reports, a report documenting performance installed in a representative application in an operationally relevant environment, a full scale prototype installed in a shelter or body bag, level 2 engineering CAD drawings and a Phase III scale up plan.

PHASE III DUAL USE APPLICATIONS: Commercial applications for this product include body bags, dry bags, dry suits, filter housings and hazmat collection. High pressure closures can take the place of chemical adhesives, textile heat welds and other permanent closure methods.

REFERENCES:

    • MIL-STD-810 Environmental Engineering Considerations and Laboratory Tests methods 500-520: http://www.atec.army.mil/publications/Mil-Std-810G/Mil-Std-810G.pdf

 

    • 49 CFR Parts 105-180, collectively called the Hazardous Materials Regulations (HMR) specifically 173.196(d)(2). Http://www.ecfr.gov/cgi-bin/text-idx?tpl=/ecfrbrowse/Title49/49tab_02.tpl

 

    • The Defense Transportation Regulations (DTR) 4500.9-R: http://www.transcom.mil/dtr/part-i/dtr_part_i_app_i.pdf#search=hazardous&zoom=100

 

    • Joint regulation AFMAN 24-204_IP, Preparing Hazardous Materials for Military Air Shipments: http://www.wpafb.af.mil/shared/media/document/AFD-121204-014.pdf

 

    • Berry Amendment:
      http://web.ita.doc.gov/tacgi/eamain.nsf/BerryAmendment/Berry%20Amendment?Opendocument

 

    • MIL-STD-1472 Human Engineering: http://www.public.navy.mil/comnavsafecen/Documents/acquisition/MIL-STD-1472G%5B1%5D.pdf

 

  • TOP 8-2-501: Permeation and Penetration Testing of Air-Permable, Semi-permeable,and Impermeable Materials with Chemical Agents or Simulants (Swatch Testing) http://www.nist.gov/national-security-standards/upload/global_docs_TECMIPT_TTOP_08-2-501.pdf

KEYWORDS: Zipper, closure, chemical, CBRN, hermetic, seal, shelter, air transportation, Ebola

  • TPOC-1: Greg Gudejko
  • Phone: 508-233-5848
  • Email: gregory.gudejko@us.army.mil
  • TPOC-2: Kristian Donahue
  • Phone: 508-233-5202
  • Email: kristian.donahue@us.army.mil

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