| 摘要 |
Fold-flat personal respiratory protection devices that have a flat substantially rectangular central portion having first and second edges, at flat first member joined to the first edge of the central portion through either a fold-line, seam, weld or bond, said fold, bond, weld or seam of the first member being substantially coextensive with said first edge of said central portion, and a flat second member joined to the second edge of the central portion through either a fold-line, seam, weld or bond, the fold, bond, weld or seam of the second member being substantially coextensive with said second edge of said central portion. At least one of the central portion and first and second members are formed from filter media. The device is capable of being folded flat for storage with the first and second members being in at least partial face-to-face contact with a common surface of the central portion and, during use, is capable of forming a cup-shaped air chamber over the nose and mouth of the wearer with the unjoined edges of the central portion and first and second members adapted to contact and be secured to the nose, cheeks and chin of the wearer. The outer boundary of the unjoined edges which are adapted to contact the nose, cheeks and chin of the wearer are less than the perimeter of the device in the flat folded storage state. Also provided are process for preparing such devices.
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