| 摘要 |
A filtering face mask 10 that has a harness 14 and a mask body 12. The mask body 12 is structured such that a snug facial fit can be achieved without use of additional components such as an elastomeric face seal, nose foam, or nose clip. The mask body 12 includes a filtering structure 18 and a cup-shaped shaping layer 20 where the latter comprises a closed cell foam layer that has a plurality of fluid permeable openings located in it. The openings occupy at least 30% of the total surface area of the shaping layer, including a mid region of the shaping layer. The filtering structure is coextensively disposed over the shaping layer. The shaping layer 20 makes contact with the wearer's face at the mask body perimeter 19 when the respirator is being worn. Despite the open nature of the foam shaping layer over much of its surface area, the use of a foam shaping layer, in conjunction with a coextensive filtering structure, provides sufficient structural integrity or stiffness to prevent mask body collapse during respirator use while also exhibiting a low pressure drop to allow for low breathing resistance and extended wearer comfort. |
