3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

3m Innovation Properties Company

Philip D Eitzman

Thomas J Xue

Steven M Heilmann

Louis C Haddad

Alan D Rousseau

Todd W Johnson

Gary J Drtina

Frederick W Hyde

Marvin E Jones

Seyed Abolhassan Angadjivand

Dean R Duffy

Zhiqun Zhang

Glen O Gregerson

Michael G Williams

Bryan L Gerhardt

Jimmy Minh Le

Michael G Schwartz

Nhat Ha Thi Nguyen

Jerald K Rassmussen

Various embodiments of an exhalation valve and a filtering face mask that includes such exhalation valve are disclosed. The exhalation valve can include a valve seat and a valve flap disposed over a seal surface and an orifice of the valve seat. The valve flap is adapted to be sealed against the seal surface of the valve seat when the exhalation valve is disposed in a closed configuration such that fluid is prevented from flowing through the valve seat. The orifice of the valve seat can include a substantially circular shape in a plane defined by a first major surface of the valve seat. Further, the seal surface can circumscribe the orifice and can include a substantially noncircular shape in the plane defined by the first major surface of the valve seat.

Exhalation valve and respirator including same

A pleated air filter media is provided. The pleated air filter media comprises a plurality of upstream linear bridging filaments that are extrusion-bonded to at least some of a plurality of upstream pleat tips of a fibrous web, and a plurality of downstream continuous-contact filaments that are extrusion-bonded to a downstream face of the fibrous web. Methods of making and using the same are also provided.

Pleated air filter with bridging filaments and continuous-contact filaments

Valve cover

Valve cover with diamond pattern

Valve cover with openings

Respirator having folded nose region

A method for imparting an electrostatic charge to a nonwoven fibrous web . The fibrous web is contacted with a liquid solution that includes water and a non-aqueous water soluble component, followed by drying . The resulting dried product is an electret article that could be used as an air filter in, for example, a respirator

Process of making a fibrous electret web

A method of charging fibrous webs with nonaqueous polar liquids. A web that contains nonconductive fibers is wetted with a nonaqueous polar liquid The web is then substantially dried to provide a fibrous electret web. The fibrous electret web can be used as a filter in a filtration face mask that is adapted to cover the nose and mouth of the wearer. The present method has the advantage over known charging methods in that the nonaqueous liquid requires less energy for drying than is required for aqueous liquids. Additionally, many filter webs can be directly wetted with nonaqueous liquids, which cannot be easily wetted with aqueous liquids.

Method of making a fibrous electret web using a nonaqueous polar liquid

A method for imparting an electrostatic charge to a nonwoven fibrous web . The fibrous web is wetted with a wetting liquid , followed by being saturated with an aqueous polar liquid and drying . The resulting dried product is an electret article that could be used as an air filter in, for example, a respirator

Method and apparatus for making a fibrous electret web using a wetting liquid and an aqueous polar liquid

A method and apparatus for charging fibers that contain a nonconductive polymer. A polar liquid is sprayed onto free-fibers and the free-fibers are then collected to form an entangled nonwoven fibrous web that may contain a portion of the polar liquid. The nonwoven web is then dried By applying an effective amount of polar liquid onto the nonconductive free-fibers before forming the nonwoven web followed by drying the individual fibers become charged. The method and apparatus enable the fibers to be charged during web manufacture without subsequent processing.

Method and apparatus for making a nonwoven fibrous electret web from free-fiber and polar liquid

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Lake Elmo, MN, United States of America

Philip D Eitzman