| 主权项 |
1. A venting apparatus having an opening therein for venting an enclosure, said venting apparatus comprising:
a gas-permeable, porous venting element affixed within said venting apparatus to cover said opening and forming a liquid-tight, gas-permeable seal of said opening, said porous venting element having a porous surface extending across the opening; said porous venting element comprising a polymeric membrane, having a porosity of less than 80% and a plurality of surface indentations in said porous surface, said plurality of surface indentations being defined by corresponding compressed regions in said porous surface in a portion of an area of said porous surface of said porous venting element that covers said opening, each of said plurality of surface indentations having a z axis differential of at least 12 microns from a top portion of said porous surface to an inner most surface of the surface indentation, wherein the porous surface includes a plurality of uncompressed regions adjacent the compressed regions, and wherein said plurality of surface indentations cover at least 20% of an area of the porous surface and provide an air flow recovery after liquid exposure greater than an air flow recovery of the uncompressed regions. |
