Filter media comprising non-woven fiber webs and having one or more advantageous structural properties are generally described. In some embodiments, a filter media and/or non-woven fiber web described herein has one or more properties that are both beneficial and easily obtainable by undulating the non-woven fiber web, such as by performing a creping procedure. This property may be characteristic of the procedure employed to form the undulations (e.g., creping and/or microcreping), or may be attainable via one or more methods of undulation.

The air filter medium of the present invention is an air filter medium including a stack of a porous polytetrafluoroethylene (PTFE) membrane and an air-permeable support member, a repulsive force generated in the medium when the medium is compressed in a thickness direction thereof is equal to or greater than 30 kPa and equal to or less than 150 kPa at a compression ratio of 30%, and at least one main surface of the air filter medium is formed by the air-permeable support member and has a maximum coefficient of friction of 24 gf or less. The air filter medium of the present invention is an air filter medium that uses a porous PTFE membrane and in which a decrease in collection efficiency due to pleating is inhibited.

A nonwoven web comprising a layer of polymeric fibers, wherein, based on the total number of polymeric fibers, at least 10% the polymeric fibers in said layer are coarse fibers having a fiber diameter of 4 μm or more, and at least 10% of the polymeric fibers in said layer are fine fibers having a fiber diameter of 2 μm or less. Also described herein is a method for making the nonwoven web, comprising melt-blowing a polymer mixture comprising two immiscible or partially miscible polymers.

Filter media including a filtration layer comprising fibers (e.g., synthetic fibers) comprising a flame retardant and related components, systems, and methods associated herewith are provided. In some embodiments, a filtration layer may include a nonwoven web (e.g., wet-laid nonwoven web) comprising fibers including a certain flame retardant that has a relatively low concentration of or is substantially free of certain undesirable and/or toxic components (e.g., halogens). In certain embodiments, the nonwoven web may also comprise a blend of fibers. For instance, in some embodiments, the nonwoven web may also comprise a blend of coarse and fine diameter synthetic fibers that impart beneficial performance properties to the filtration layer. In some embodiments, the filtration layer may be designed to have a desirable flame retardancy (e.g., F1 rating, K1 rating) and performance properties without compromising certain mechanical properties (e.g., pleatability of the media) and/or environmental attributes (e.g., relatively low toxicity). Filter media described herein may be particularly well-suited for applications that involve filtering air, though the media may also be used in other applications.

The invention relates to a respiratory protection mask made of polyvinylidene fluoride and to a method for manufacturing said mask. The invention also relates to a method for reconditioning said mask. The invention also relates to a method for recycling this respiratory protection mask.

A system for thermally bonding nonwoven fibers of assemblages of nonwoven fibers loosely held together may include a processing duct including an inlet end, an outlet end, and an intermediate portion extending between the inlet end and the outlet end. The system also may include one or more heat inlets located in the intermediate portion and configured to facilitate introduction of heat and air flow into the intermediate portion. The system further may include an inlet air feed at the inlet end and configured to separate the assemblages upon entry into the inlet end and propel the assemblages into the intermediate portion. The system also may include one or more heating devices configured to heat the assemblages as the assemblages are conveyed toward the outlet end to form processed assemblages, each of the processed assemblages including at least some nonwoven fibers adhered to one another.

A face mask for protection against infectious agents includes: a filter medium from spun nonwoven, which has multicomponent filaments, which are split at least partially into elementary filaments. In an embodiment, the filter medium includes at least two layers of spun nonwoven. In an embodiment, each layer of spun nonwoven has a basis weight of 10 to 100 g/m.sup.2.

A thermally bonded filtration media that can be used in high temperature conditions in the absence of any loss of fiber through thermal effects or mechanical impact on the fiber components is disclosed. The filter media can be manufactured and used in a filter unit or structure, can be placed in a stream of removable fluid, and can remove a particulate load from the mobile stream at an increased temperature range. The combination of bi-component fiber, other filter media fiber, and other filtration additives provides an improved filtration media having unique properties in high temperature, high performance applications.

A long-fiber nonwoven fabric includes fibers having a birefringence (Δn) of more than or equal to 0.005 and less than or equal to 0.020 and an average fiber diameter of more than or equal to 30 μm and less than or equal to 60 μm, and has a basis weight amount of more than or equal to 50 g/m.sup.2 and less than or equal to 120 g/m.sup.2, an average value of Gurley bending resistances in an MD direction and a CD direction according to JIS L1096 (2010) 8.22.1 Method A of more than or equal to 100 mg and less than or equal to 200 mg, and a value of the Gurley bending resistance in the MD direction/the Gurley bending resistance in the CD direction of less than or equal to 3.0.

A washing machine (900) includes a drum (910) in which washing operations are carried out, a drainage hose (950) fluidically connected to the drum (910) and fluidically connectable to a drainage system and a filter group (1) positioned along the drainage hose (950). The filter group (1) filters synthetic microfibers of micrometric size and is made of a non-woven fabric having synthetic fibers.