A filter pleat pack of the present disclosure includes an air filter medium folded into pleats. The air filter medium includes a laminate of a polytetrafluoroethylene (PTFE) porous membrane and an air-permeable supporting member. When a cut surface of the filter pleat pack is observed, the cut surface being taken along a plane perpendicularly crossing a pleat line of the filter pleat pack, the PTFE porous membrane has a first converging portion, a split portion, and a second converging portion in this order in a direction in which the membrane extends. In the split portion, the PTFE porous membrane is split into a plurality of layers in a thickness direction of the membrane and the plurality of layers are spaced apart from each other. At the first converging portion and the second converging portion, the plurality of layers converge into one layer. The filter pleat pack of the present disclosure is a filter pleat pack for which a collection efficiency decrease resulting from pleating is reduced.

A filter pleat pack of the present disclosure includes an air filter medium folded into pleats, wherein the air filter medium includes a laminate of a polytetrafluoroethylene (PTFE) porous membrane and an air-permeable supporting member, and the air filter medium has a shrinkage rate of 50% or more, the shrinkage rate being determined by a formula (d2−d1)/d2, where d1 is a smallest thickness of the PTFE porous membrane in a folding area of the air filter medium folded into pleats and d2 is a thickness of the PTFE porous membrane in a flat area of the air filter medium. The filter pleat pack of the present disclosure is a filter pleat pack for which a collection efficiency decrease resulting from pleating is reduced.

A depth filter with excellent filtration accuracy and pressure resistance performance even for fluids containing high density and high viscosity powder fine particles. A depth filter having a base material layer, a filtration layer, and a skin layer, in that order, wherein: the substrate layer and the skin layer are layers made by a nonwoven fabric being wound and thermally fused; the filtration layer is a laminate in which at least a nonwoven fabric and a net are laminated, being wound twice or more; and the nonwoven fabric contained in the filtration layer contains a mixed-fiber nonwoven fabric containing two or more types of fibers with mutually different average fiber diameters.

A method for controlling fiber cross-alignment in a nanofiber membrane, comprising: providing a multiple segment collector in an electrospinning device including a first and second segment electrically isolated from an intermediate segment positioned between the first and second segment, collectively presenting a cylindrical structure, rotating the cylindrical structure around a longitudinal axis proximate to an electrically charged fiber emitter; electrically grounding or charging edge conductors circumferentially resident on the first and second segment, maintaining intermediate collector electrically neutral; dispensing electrospun fiber toward the collector, the fiber attaching to edge conductors and spanning the separation space between edge conductors; attracting electrospun fiber attached to the edge conductors to the surface of the cylindrical structure, forming a first fiber layer; increasing or decreasing rotation speed of the cylindrical structure to alter the angular cross-alignment relationship between aligned nanofibers in adjacent layers, the rotation speed being altered to achieve a target relational angle.

The invention relates to a face mask comprising a compound structure with an inner layer and two sandwich layers, wherein the inner layer is made from a filter material for filtering particles and germs, the sandwich layers are made from a textile material, the inner layer is sandwiched by the sandwich layers, and the sandwich layers are bonded to the inner layer at least in sections along the perimeter of the face mask and in sections in the inner area of the face mask.

In this way, a reusable face mask with enhanced filtration efficiency is provided.

The present application relates to biodegradable and ecofriendly fabrics and methods for making the same. The fabrics are made from PLA fibers and/or yarns, and have one-way or two-way filtration characteristics and/or moisture management characteristics with controlled porosity and smooth or textured surface, the moisture management characteristics arise from a combined effect of material properties and fabric structure.

Intra-nasal filter devices and methods for their manufacture and use are disclosed. An intra-nasal filter device includes: a first stage filter proximate the septum; and a second stage filter comprising a flexible material extending upwardly from the first filter stage filter; wherein the flexible material comprises: an impedance in the range of 0.02 to 0.2 cmH.sub.2O; an effective cross-sectional area in the range of 0.2 to 2 square inches; and a plurality of radially extending geometric structures disposed along an axial length of the second stage.

A protective fabric which includes at least one structural layer and a ceramic composite material layer fixed to the at least one structural layer, is provided. The structural layer can include a non-woven material made from or containing synthetic fibers. The ceramic composite material layer is formed of ceramic composite material powder which includes a ceramic carrier, and iron-silver crystals containing zero-valent iron and zero-valent silver supported on the ceramic carrier. The protective fabric is effective for removing VOCs, suppressing bacterial growth, and filtering or inactivating virus, such as SARS-CoV-2 virus. Protective products or articles incorporating the protective fabric are also provided.

The present invention relates to an air filter, and more particularly to a multilayer air filter incorporating nanosilver.

A filter medium has a substrate layer and a nanofiber layer arranged on the substrate layer. Adhesive fibers are laid onto the nanofiber layer and connect the nanofiber layer with the substrate layer. The nanofiber layer is located between the substrate layer and the adhesive fibers.