1
David L Braun: Particle-loaded microfiber sheet product and respirators made therefrom. Minnesota Mining and Manufacturing Company, Alexander Sell Steldt & DeLaHunt, July 27, 1976: US03971373 (261 worldwide citation)

A self-supporting durable flexible conformable low-pressure-drop porous sheet product that contains a uniform three-dimensional arrangement of discrete solid particles. This sheet product comprises, in addition to the particles, a web of melt-blown microfibers in which the particles are uniformly di ...


2
David L Braun, Donald L Melvin: Respiratory mask having a rigid or semi-rigid, insert-molded filtration element and method of making. Minnesota Mining and Manufacturing Company, Donald M Sell, Roger R Tamte, December 13, 1988: US04790306 (60 worldwide citation)

A filtering device is made by inserting into an injection mold a porous, rigid or semi-rigid filtration element that has inflow and outflow faces separated by a peripheral surface and then injecting resin into the flow channel of the mold at a pressure and temperature such that the resin does not si ...


3
David L Braun, Peter O Rekow: Bonded adsorbent structures and respirators incorporating same. Minnesota Mining and Manufacturing Company, Gary L Griswold, Walter N Kirn, Eloise J Maki, July 23, 1991: US05033465 (49 worldwide citation)

Shaped porous filtering structures of substantially uniform thickness and density particularly suited for filtration of gases and vapors comprising spaced adsorbent granules unified into a solid, self-sustaining, unitary, impact-resistant body by adherent binder particles. Respirators incorporating ...


4
David L Braun: Powered air respirator and cartridge. Minnesota Mining and Manufacturing Company, Donald M Sell, James A Smith, Lorraine R Sherman, July 31, 1984: US04462399 (48 worldwide citation)

A high efficiency rigid or semi-rigid air filter cartridge for use in the helmet of a powered air respirator comprising a lightweight, open-topped, trough-shaped frame having an entrance at one end for attachment to an air discharge port of a fan motor housing assembly, filter media sealed about its ...


5
David L Braun, James E Steffen: Fibrous filtration face mask having corrugated polymeric microfiber filter layer. Minnesota Mining and Manufacturing Company, Gary L Griswold, Walter N Kirn, Karl G Hanson, August 12, 1997: US05656368 (47 worldwide citation)

A composite structure contains a lofty corrugated nonwoven web of polymeric microfiber that is maintained in a corrugated condition by securing a fabric to the corrugated web at the valleys of the corrugations. The composite structure is made without substantially effecting web loft by (i) introduci ...


6
David L Braun, John A Trine: Vapor sampling device. Minnesota Mining and Manufacturing Company, Alexander Sell Steldt & DeLaHunt, April 20, 1976: US03950980 (44 worldwide citation)

A device for measuring the presence or time-average amounts of at least one selected gas in a mixture thereof which comprises an enclosure having therewithin at least one substance which interacts with the gas to be monitored. Attenuating means associated with the enclosure regulate gas movement wit ...


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David L Braun, Peter O Rekow: Bonded adsorbent structures and respirators incorporating same. Minnesota Mining and Manufacturing Company, Gary L Griswold, Walter N Kirn, Eloise J Maki, January 7, 1992: US05078132 (39 worldwide citation)

Shaped porous filtering structures of substantially uniform thickness and density particularly suited for filtration of gases and vapors comprising spaced adsorbent granules unified into a solid, self-sustaining, unitary, impact-resistant body by adherent binder particles, respirators incorporating ...


9
David L Braun: Unidirectional fluid valve. Minnesota Mining and Manufacturing Company, Donald M Sell, Walter N Kirn, David W Anderson, June 19, 1990: US04934362 (37 worldwide citation)

The exhalation valve of a respiratory face mask, while taking up only a small area, can afford extraordinarily low pressure drop for easy breathing if constructed with a valve seat having a seal edge that defines an orifice and also forms a parabola in the plane bisecting the mask. Preferably the se ...


10
David L Braun, James E Steffen: Filter having corrugated nonwoven webs of polymeric microfiber. Minnesota Mining and Manufacturing Company, Karl G Hanson, June 9, 1998: US05763078 (36 worldwide citation)

A filter that is capable of removing particulate and gaseous contaminants from a fluid, which filter comprises: