3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

James E Springett

Seyed Abolhassan Angadjivand

John M Brandner

Timothy J Lindquist

Andrew R Fox

John D Stelter

Marvin E Jones

Leonard W Barrett

Michael R Berrigan

William J Kopecky

Roberta C Harper

Thomas I Insley

A flat-fold respirator is made from a stiff filtration panel joined to the remainder of the respirator through at least one line of demarcation. The panel contains a porous monocomponent monolayer nonwoven web that contains charged intermingled continuous monocomponent polymeric fibers of the same polymeric composition and that has sufficient basis weight or inter-fiber bonding so that the web exhibits a Gurley Stiffness greater than 200 mg and the respirator exhibits less than 20 mm HO pressure drop. The respirator may be formed without requiring additional stiffening layers, bicomponent fibers, or other reinforcement and can be flat-folded for storage. Scrap from the manufacturing process may be recycled to make additional stiff filtration panel web.

Flat-fold respirator with monocomponent filtration/stiffening monolayer

A molded respirator is made from a monocomponent monolayer nonwoven web containing a bimodal mass fraction/fiber size mixture of intermingled continuous monocomponent polymeric microfibers and larger size fibers of the same polymeric composition. The respirator is a cup-shaped porous monocomponent monolayer matrix whose matrix fibers are bonded to one another at least some points of fiber intersection. The matrix has a King Stiffness greater than 1 N. The respirator may be formed without requiring stiffening layers, bicomponent fibers, or other reinforcement in the filter media layer.

Process of making a molded respirator

A porous monocomponent nonwoven web contains a bimodal mass fraction/fiber size mixture of intermingled continuous microfibers and larger size fibers of the same polymeric composition. There are at least five times as many microfibers as larger size fibers, and a histogram of the mass fraction of fibers vs. fiber size exhibits a larger size fiber mode greater than 10 &#x3bc;m. The web may be made by flowing fiber-forming material through a die cavity having larger size orifices and at least five times as many smaller size orifices to form filaments, attenuating the filaments into fibers and collecting the attenuated fibers to form the nonwoven web. The web is especially well suited to the manufacture of self-supporting three dimensional articles such as molded cup-shaped respirators and pleated air filters.

Process of making a monocomponent non-woven web

A pleated filter is made from a monocomponent monolayer nonwoven web containing a bimodal mass fraction/fiber size mixture of intermingled larger size and smaller size continuous monocomponent polymeric fibers of the same polymeric composition. Rows of pleats are formed in the nonwoven web, and the pleated web is cut to a desired size and shape to provide a filter element containing a self-supporting porous monocomponent monolayer matrix of fibers bonded to one another at least some points of fiber intersection and having an average initial submicron efficiency of at least 15% at a 1.52 meters/sec face velocity. The filter element is deformation resistant without requiring stiffening layers, bicomponent fibers or other reinforcing measures in the filter media layer.

Pleated filter with bimodal monolayer monocomponent media

Shaped filtration articles are made from a monocomponent nonwoven web formed by flowing first and second fiber-forming materials of the same polymeric composition through first and second die cavities in respective fluid communication with first and second sets of orifices in a meltblowing die tip. The first fiber-forming material flows at a lesser flow rate or viscosity through the first die cavity and first set of orifices to form a set of smaller size filaments and the second fiber-forming material flows at a greater flow rate or viscosity through the second die cavity and second set of orifices to form a set of larger size filaments. The collected nonwoven web contains a meltblown bimodal mass fraction/fiber size mixture of intermingled continuous microfibers and larger size fibers of the same polymeric composition.

Method for making shaped filtration articles

A porous nonwoven web and method of making are disclosed, wherein the web contains meltblown fibers and staple fibers. The meltblown fibers may be present as a bimodal mixture of microfibers and mesofibers, and comprise an intermingled mixture with staple fibers further intermingled therein.

Meltblown fiber web with staple fibers

A molded respirator and method of making are disclosed, wherein the molded respirator is made from a porous nonwoven web containing meltblown fibers and staple fibers. The meltblown fibers may be present as a bimodal mixture of microfibers and mesofibers, and comprise an intermingled mixture with staple fibers further intermingled therein. The molded respirator may also contain at least one secondary filtration layer.

Molded respirator comprising meltblown fiber web with staple fibers

Monocomponent monolayer meltblown web and meltblowing apparatus

A molded respirator is made from a monocomponent monolayer nonwoven web containing a bimodal mass fraction/fiber size mixture of intermingled continuous monocomponent polymeric microfibers and larger size fibers of the same polymeric composition. The respirator is a cup-shaped porous monocomponent monolayer matrix whose matrix fibers are bonded to one another at at least some points of fiber intersection. The matrix has a King Stiffness greater than 1 N. The respirator may be formed without requiring stiffening layers, bicomponent fibers, or other reinforcement in the filter media layer.

Molded monocomponent monolayer respirator with bimodal monolayer monocomponent media

A pleated filter is made from a monocomponent monolayer nonwoven web containing a bimodal mass fraction/fiber size mixture of intermingled larger size and smaller size continuous monocomponent polymeric fibers of the same polymeric composition. Rows of pleats are formed in the nonwoven web, and the pleated web is cut to a desired size and shape to provide a filter element containing a self-supporting porous monocomponent monolayer matrix of fibers bonded to one another at at least some points of fiber intersection and having an average initial submicron efficiency of at least 15% at a 1.52 meters/sec face velocity. The filter element is deformation resistant without requiring stiffening layers, bicomponent fibers or other reinforcing measures in the filter media layer.

A filtering face mask that includes a mask body that is adapted to fit over the nose and mouth of a person and a harness that is attached to the mask body. The mask body comprises i) a first shaping layer that has been molded; ii) a second shaping layer that has been molded; iii) a filtration layer that is disposed between the first and second shaping layers; iv) a first adhesive layer that adheres the first shaping layer to the filtration layer; and v) a second adhesive layer that adheres the second shaping layer to the filtration layer.

Crush resistant filtering face mask

A filter element that comprises a porous molded web &prime; that contains thermally bonded staple fibers and non-thermally bonded electrically charged microfibers . The molded web is retained in its molded configuration, at least in part, by bonds between the staple fibers at points of fiber intersection . The web may be molded, for example, into the shape of filtering face mask

Molded filter element that contains thermally bonded staple fibers and electrically-charged microfibers

Molded respirators containing an air-permeable, sorbent-particle-containing layer between air-permeable particle-retaining layers. The particle-containing layer is stretchable during shaping without tearing or significant loss of particles. At least some of the fibers in the particle-containing layer are sufficiently tacky after being formed by themselves into a particle-free web and cooled to room temperature so that the web will adhere to itself. The respirators can be molded from flat webs without the need to fabricate the particle-containing layer into a shaped preform.

Growing community of inventors

Hudson, WI, United States of America

James E Springett