Embodiments relate generally to systems and methods for absorbing moisture within a face mask worn by a user. A face mask may comprise at least one layer of filtration material. configured to filter one or more harmful substances from the air breathed by a user; at least one layer of absorbent material configured to absorb moisture exhaled by the user, wherein the at least one layer of absorbent material spans the entire inner surface area of the mask; at least one layer of waterproof material located between the at least one layer of filtration material and the at least one layer of absorbent material configured to prevent moisture from the absorbent material from contacting the filtration material; and at least one layer of anti-bacterial material located adjacent to the at least one layer of absorbent material and forming the inner surface of the mask.

It is provided that an electret having excellent filtering performance and a filter using the electret even in a case where polyolefin resin and magnesium element are contained. An electret comprising a polyolefin resin and a nitrogen-containing compound, wherein 0.1 to 5 parts by mass of the nitrogen-containing compound is contained to 100 parts by mass of the polyolefin resin, a proportion of a magnesium element contained in the electret is 5 to 100 ppm, and a QF value represented by the following formula is not less than 1.00 mmAq.sup.−1 when particles having particle diameters of 0.3 to 0.5 μm are to be collected.

QF [mmAq.sup.−1]=— [1n (particle penetration (%)/100)]/[ventilation resistance (mmAq)]

Filter media including out-of-plane solid elements are generally described. Inventive methods of forming them and uses thereof are also described.

A filtration medium for a filter, having high dust collection efficiency, low pressure loss, a long service life and sufficient processing strength into a filter. A combined fiber nonwoven fabric includes first fibers having a mean fiber diameter of less than 200 nanometers, and second fibers having a mean fiber diameter in the range of 200 to 5000 nanometers, in which basis weight of the combined fiber nonwoven fabric is in the range of 2.1 to 15.0 g/m.sup.2.

A filter reinforcing material is disclosed that does not cause peeling or pleat adhesion at the time of pleating, is excellent in pleating, and has high stiffness. A filter reinforcing material includes a bonding layer comprising a thermal bonded nonwoven including thermal bondable short fibers, and a reinforcing layer comprising a nonwoven including high-melting fibers having a higher melting point than a melting point of the thermal bondable short fibers having the lowest melting point in the bonding layer by 30 C. or more. Further, the bonding layer preferably comprises two or more kinds of thermal bondable short fibers with a fineness difference of more than or equal to 5 dtex.

A face mask (100) may comprise at least one layer of filtration material (218) configured to filter one or more harmful substances from the air breathed by a user; at least one layer of absorbent material (214) configured to absorb moisture exhaled by the user, wherein the at least one layer of absorbent material (214) spans the entire inner surface area of the mask (100); at least one layer of waterproof material (216) located between the at least one layer of filtration material (218) and the at least one layer of absorbent material (214) configured to prevent moisture from the absorbent material from contacting the filtration material; and at least one layer of anti-bacterial material (212) located adjacent to the at least one layer of absorbent material (214) and forming the inner surface of the mask (100). The face mask (100) can absorb moisture exhaled by a user.

A filter medium for filtration of an air stream includes: a non-woven having a plurality of bicomponent fibers. The non-woven includes a single-layer fiber composite having a first structure of bicomponent fibers and a second structure of continuous bicomponent fibers. The second structure engages with the first structure. In an embodiment, the bicomponent fibers include at least two polymer components. The at least two polymer components of the bicomponent fibers differ in melting point by at least 15 degrees and have a cover-core fiber structure or a side-by-side fiber structure.

The invention concerns spunbond nonwoven fabrics comprising a plurality of bicomponent filaments, the bicomponent filaments having a segmented pie cross-sectional configuration including a polycarbonate component and a polypropylene component, wherein a ratio of the polypropylene component to the polycarbonate component is between about 5:95 and about 95:5.

A fiber including olefin-based resin, wherein temperatures of the olefin-based resin losing five percent by weight and the fiber losing five percent by weight have a difference of 20 degrees Celsius or below according to thermogravimetric measurements. The fiber can reduce the leaching of impurities with low molecular weight by controlling the deterioration of olefin-based resin when heated during its spinning process.

A filter reinforcing material is disclosed that does not cause peeling or pleat adhesion at the time of pleating, is excellent in pleating, and has high stiffness. A filter reinforcing material includes a bonding layer comprising a thermal bonded nonwoven including thermal bondable short fibers, and a reinforcing layer comprising a nonwoven including high-melting fibers having a higher melting point than a melting point of the thermal bondable short fibers having the lowest melting point in the bonding layer by 30? C. or more. Further, the bonding layer preferably comprises two or more kinds of thermal bondable short fibers with a fineness difference of more than or equal to 5 dtex.