waterproof, air permeable membrane
HKorh...@t-online.de
Hi, for a pharmaceutical application I am looking for a thin waterproof,
air permeable membrane (filter paper, textile ?). In a mixed water-gas
ambient it should resist to absorb water under low pressure for at least
15 minutes, but at the same should should be highly permeable for air. I
am aware that it is difficult to have both, but maybe somebody got an
idea. Thanks a lot
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William R. Penrose
>Hi, for a pharmaceutical application I am looking for a thin waterproof,
>air permeable membrane (filter paper, textile ?). In a mixed water-gas
>ambient it should resist to absorb water under low pressure for at least
>15 minutes, but at the same should should be highly permeable for air.
You can buy porous Teflon, polypropylene, PVdF, and other hydrophobic plastics
from a number of suppliers. These will freely allow air to flow, while
surface tension will prevent the flow of liquid water up to some maximum
pressure.
If this is not appropriate, then thin solid membranes of silicone, Teflon, or
polyethylene will allow permeation of air (slowly), while water will only
permeate as water vapor. "Thin" means 25 -100 microns.
Bill
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Bill Penrose, President, Custom Sensor Solutions, Inc.
526 West Franklin Avenue, Naperville IL 60540, USA
630-548-3548, fax 630-369-9618, email wpen...@interaccess.com
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Purveyors of contract R&D and gas sensor-based product
development to this and nearby galaxies.
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