Abstract: A respirator 10 includes a compressible filter element 12, a filter element retainer 14, and a face piece 16. The respirator is unique in that the filter element 12 compresses when installed in the retainer 14, allowing a friction fit to be maintained between the filter element 12 and retainer 14. The friction fit enables the filter element 12 to be readily replaced when its service life has expired.

Abstract: A respirator 10 includes a compressible filter element 12, a filter element retainer 14, and a face piece 16. The respirator is unique in that the filter element 12 compresses when installed in the retainer 14, allowing a friction fit to be maintained between the filter element 12 and retainer 14. The friction fit enables the filter element 12 to be readily replaced when its service life has expired.

Abstract: 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) introducing the nonwoven web to the ends of a plurality of spaced paddles, (ii) causing the spacing between the ends of the paddles to decrease to corrugate the nonwoven web, and (iii) securing the fabric to the corrugated nonwoven web at the valleys of the corrugations. A composite structure of this construction made by this method provides very good filtration performance, making it particularly suitable for use as a filter in a cup-shaped face mask. The composite structure also is very suitable for use as thermal insulation in apparel.

Abstract: A diffusional gas transfer system and method having a membrane disposed between a first gas domain and a second gas domain. The first gas domain includes a first mechanism for directing a first environmental gas flow transversely over and in contact with a first surface of the membrane. The second gas domain includes a second mechanism for directing a second environmental gas flow transversely over and in contact with a second surface of the membrane. The membrane is a diffusional gas transfer medium having a multiplicity of tortuous pathways extending from the first surface of the membrane to the second surface of the membrane. The void volume fraction of the membrane is at least 0.2. The membrane is capable of substantially blocking the transfer of particles from the first gas domain to the second gas domain, while permitting the diffusion of gases between the first and second gas domains.

Abstract: Corrugating apparatus that includes paddles and an ultrasonic welding device. The paddles are attached at one end to a transport that moves about a path. The paddles extend radially from the transport, and each paddle has a free end that is capable of supporting a web as the paddles move about the path. The free ends of the paddles are able to move towards each other to cause the web to corrugate. The ultrasonic welding device is located downstream to where the paddles' free ends move towards each other. The ultrasonic welding device has a horn and an anvil, and the anvil includes the free ends of the paddles.

Abstract: Apparel having thermal insulation containing a corrugated nonwoven web and a means for retaining the shape of a corrugated web. The shape-retaining means is not coextensive with the corrugated nonwoven web and is secured to the valleys of the corrugations. The corrugated nonwoven web has a solidity of 0.1 or less and contains microfiber and crimped staple fibers that have a percent crimp of at least 15 percent.

Abstract: Corrugating apparatus that includes paddles and an ultrasonic welding device. The paddles are attached at one end to a belt that moves about a path. The paddles extend radially from the belt, and each paddle has a free end that supports a web as the paddles move about the path. The free ends of the paddles are able to move towards each other to cause the web to corrugate. The ultrasonic welding device is located downstream to where the paddles' free ends move towards each other. The ultrasonic welding device has a horn and an anvil, and the anvil includes the free ends of the paddles.

Abstract: 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) introducing the nonwoven web to the ends of a plurality of spaced paddles, (ii) causing the spacing between the ends of the paddles to decrease to corrugate the nonwoven web, and (iii) securing the fabric to the corrugated nonwoven web at the valleys of the corrugations. A composite structure of this construction made by this method provides very good filtration performance, making it particularly suitable for use as a filter in a cup-shaped face mask. The composite structure also is very suitable for use as thermal insulation in apparel.

Abstract: A filter that is capable of removing particulate and gaseous contaminants from a fluid, which filter comprises:a first filter element that is capable of removing particulate contaminants from a fluid, the first filter element comprising a corrugated nonwoven web of polymeric microfiber having a solidity of 0.1 or less and a means for retaining the corrugated shape of the corrugated nonwoven web of polymeric microfiber, the shape-retaining means being secured to the corrugated nonwoven web to maintain the corrugated shape of the corrugated nonwoven web of polymeric microfiber, anda second filter element comprising a sorbent material capable of removing gaseous contaminants from a fluid;the first and second filter elements being secured to each other and having a shape adapted for attachment to a respirator.

Abstract: 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) introducing the nonwoven web to the ends of a plurality of spaced paddles, (ii) causing the spacing between the ends of the paddles to decrease to corrugate the nonwoven web, and (iii) securing the fabric to the corrugated nonwoven web at the valleys of the corrugations. A composite structure of this construction made by this method provides very good filtration performance, making it particularly suitable for use as a filter in a cup-shaped face mask. The composite structure also is very suitable for use as thermal insulation in apparel.

Abstract: 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) introducing the nonwoven web to the ends of a plurality of spaced paddles, (ii) causing the spacing between the ends of the paddles to decrease to corrugate the nonwoven web, and (iii) securing the fabric to the corrugated nonwoven web at the valleys of the corrugations. A composite structure of this construction made by this method provides very good filtration performance, making it particularly suitable for use as a filter in a cup-shaped face mask. The composite structure also is very suitable for use as thermal insulation in apparel.

Abstract: Thermal insulation contains a corrugated nonwoven web and a means for retaining the shape of a corrugated web. The shape-retaining means is not coextensive with the corrugated nonwoven web and is secured to the valleys of the corrugations. The corrugated nonwoven web has a solidity of 0.1 or less and contains microfiber and crimped staple fibers that have a percent crimp of at least 15 percent.

Abstract: A method of making a corrugated nonwoven web of polymeric microfiber, which method comprises:(a) introducing a nonwoven web of polymeric microfiber having a solidity of 0.1 or less into a corrugating apparatus that has a plurality of paddles secured at a first end to a means for moving the paddles about a path, the nonwoven web of polymeric microfiber making contact with spaced second ends of the paddles opposite to the paddles' first ends; and(b) reducing the spacing between the second ends of the paddles to cause the nonwoven web of polymeric microfiber to become corrugated, wherein the corrugated nonwoven web of polymeric microfiber has a solidity of 0.1 or less.

Abstract: 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 such structures as the gas and vapor filtration elements and methods for making the shaped porous filtering structures are disclosed.

Abstract: A respirator harness of polymeric components and elastic straps can be made in a 2-part injection mold in a single step. The elastic straps can have superior resistance to pull-out when secured to each polymeric component by a cage that is intergral with the polymeric component, and the cage has at least one transverse rib that is fused to the elastic strap and around which the strap is stretched.

Abstract: Elastomeric nonwoven fibrous fluid filter media for removal of particulate contaminants from the fluid are provided. The filter media comprises thermoplastic elastomeric melt-blown small diameter fibers, the small diameter fibers being randomly arrayed, the filter media having substantially uniform stretch properties in all directions and whose filtration properties are independent of filter media elongations sufficient to increase the filter media surface area at least about 10 percent. The filter media is particularly useful as a prefilter on respirators.

Abstract: 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 such structures as the gas and vapor filtration elements and methods for making the shaped porous filtering structures are disclosed.

Abstract: 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 seal edge forms a rectangle as viewed against the direction of composite fluid flow through the valve, and a flexible flap is attached to a bridge across the center of the orifice at the apex of said parabola, each end of the flap being free to be lifted to allow fluid to flow through the valve.

Abstract: 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 significantly penetrate into the peripheral surface beyond its surface pores. The resin can be a thermoplastic rubber and can form the facepiece of the resirator mask. An inhalation plenum for the mask can be formed at the same time by inserting into the flow channel of the mold a thin layer of a second resin which substantially does not melt at the pressure and temperature at which the first resin is injected. A complete respirator mask can be produced at a single station in a single insert-molding operation by inserting an exhalation valve and harness attachments together with said filtration element before injecting the first resin.