| 摘要 |
The present invention relates to a filtering facepiece made from flexible filtering sheet material. The facepiece is made from a flat pocket 100 of filtering sheet material having opposed side walls 105 and 106, a generally tapering shape with an open end 104 at the larger end and a closed end 101 at the smaller end. The edge of the pocket at the closed end is outwardly bowed, e.g. defined by intersecting straight lines and/or curved lines, and the closed end is provided with fold lines 107 defining a surface which is folded inwardly of the closed end of the pocket to define a generally conical inwardly extending recess 108 for rigidifying the pocket against collapse against the face of the wearer on inhalation.
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