Abstract: A filtering face mask 10 that has a mask body and a new exhalation valve 14. The mask body is adapted to fit at least over the nose and mouth of a person to help define an interior gas space when the mask is worn. The exhalation valve 14 permits fluid communication between the interior gas space and an exterior gas space. The exhalation valve 14 has a valve seat 20 and a flap 22. The valve seat 20 includes a resilient seal surface 24 and an orifice 30 through which exhaled air may pass to leave the interior gas space. The flap 22 is mounted to the valve seat 20 such that the flap 22 makes contact with the resilient seal surface 24 when the valve is in its closed position and such that the flap 22 can move away from the seal surface 24 in response to an exhalation to allow exhaled air to pass through the orifice 30 to ultimately enter the exterior gas space.

Abstract: A filtering face mask that includes a mask body and an exhalation valve. The mask body is adapted to fit at least over the nose and mouth of a wearer to create an interior gas space when worn, and the exhalation valve is in fluid communication with the interior gas space. The exhalation valve comprises a valve seat that has a seal surface and an orifice through which an exhale flow stream may pass to leave the interior gas space. A flexible flap is mounted to the valve seat such that the flap makes contact with the seal surface when the valve is in its closed position and such that the flap can flex away from the seal surface during an exhalation to allow exhaled air to pass through the orifice to ultimately enter an exterior gas space. The flexible flap has at least first and second juxtaposed layers where at least one of the layers is stiffer or has a different elastic modulus than the other layer.

Abstract: Exhalation and inhalation valves that are sized and adapted to fit on a mask body of a personal respiratory protection device. The exhalation and inhalation valves comprise a valve seat that has a seal surface and an orifice through which an exhale flow stream may pass to leave the interior gas space. A flexible flap is mounted to the valve seat such that the flap makes contact with the seal surface when the valve is in its closed position and such that the flap can flex away from the seal surface during an exhalation to allow exhaled air to pass through the orifice to ultimately enter an exterior gas space. The flexible flap has at least first and second juxtaposed layers where at least one of the layers is stiffer or has a different elastic modulus than the other layer. These valves provide extraordinarily lower pressure drop in use, and they operate more efficiently and require less actuation power to operate.

Abstract: Exhalation and inhalation valves that are sized and adapted to fit on a mask body of a personal respiratory protection device. The exhalation and inhalation valves comprise a valve seat that has a seal surface and an orifice through which an exhale flow stream may pass to leave the interior gas space. A flexible flap is mounted to the valve seat such that the flap makes contact with the seal surface when the valve is in its closed position and such that the flap can flex away from the seal surface during an exhalation to allow exhaled air to pass through the orifice to ultimately enter an exterior gas space. The flexible flap has at least first and second juxtaposed layers where at least one of the layers is stiffer or has a different elastic modulus than the other layer. These valves provide extraordinarily lower pressure drop in use, and they operate more efficiently and require less actuation power to operate.

Abstract: A filtering face mask that includes a mask body and an exhalation valve. The mask body is adapted to fit at least over the nose and mouth of a wearer to create an interior gas space when worn, and the exhalation valve is in fluid communication with the interior gas space. The exhalation valve comprises a valve seat that has a seal surface and an orifice through which an exhale flow stream may pass to leave the interior gas space. A flexible flap is mounted to the valve seat such that the flap makes contact with the seal surface when the valve is in its closed position and such that the flap can flex away from the seal surface during an exhalation to allow exhaled air to pass through the orifice to ultimately enter an exterior gas space. The flexible flap has at least first and second juxtaposed layers where at least one of the layers is stiffer or has a different elastic modulus than the other layer.

Abstract: A filtering face mask 10 that has a mask body and a new exhalation valve 14. The mask body is adapted to fit at least over the nose and mouth of a person to help define an interior gas space when the mask is worn. The exhalation valve 14 permits fluid communication between the interior gas space and an exterior gas space. The exhalation valve 14 has a valve seat 20 and a flap 22. The valve seat 20 includes a resilient seal surface 24 and an orifice 30 through which exhaled air may pass to leave the interior gas space. The flap 22 is mounted to the valve seat 20 such that the flap 22 makes contact with the resilient seal surface 24 when the valve is in its closed position and such that the flap 22 can move away from the seal surface 24 in response to an exhalation to allow exhaled air to pass through the orifice 30 to ultimately enter the exterior gas space.

Abstract: A filtration face mask 10 that comprises a mask body 20 and a band 30. The mask body is adapted to cover the nose and mouth of a wearer and that comprises polyolefin containing fibers. The band 30 comprises an elastic constituent and a fibrous thermoplastic constituent. The fibrous thermoplastic constituent has a melting point of about 250° C. or less and is a polyolefin or a substituted polyolefin. The band is attached to the mask body by heat and pressure at securement points 23.