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Gas permeability measurements for film envelope materials

United States Patent

*** EXPIRED ***
5,750,882
May 12, 1998
View the Complete Patent at the US Patent & Trademark Office
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Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the "body-filled panel". Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials.
Ludtka; Gerard M. (Oak Ridge, TN), Kollie; Thomas G. (Oak Ridge, TN), Watkin; David C. (Clinton, TN), Walton; David G. (Knoxville, TN)
Lockheed Martin Energy Research Corporation (Oak Ridge, TN)
08/ 832,824
April 4, 1997
The United States Government has rights in this invention pursuant to contract no. DE-AC05-84OR21400 between the U. S. Department of Energy and Lockheed Martin Energy Systems, Inc.