Described are multi-layer filters of a type commonly known as “depth filters” and related devices and methods, with the filters containing a layer that includes polyaramid fiber, synthetic filter aid, and polymeric binder.

The present invention is generally related to a high capacity, high efficiency nonwoven filtration media comprising a gradient pore structure. In particular, the filtration media can comprise thermoplastic synthetic microfibers, fibrillated fibers, staple fibers, and a binder. Furthermore, the filtration media may be produced without the use of glass fibers or microglass fibers. Consequently, the filtration media of the present invention does not cause the same issues as conventional filtration media that comprises glass fibers and/or microglass fibers. Moreover, the filtration media can be used to treat fuel, lubrication fluids, hydraulic fluids, and various other industrial gases.

Disclosed are a wet non-woven fabric, the use of the wet non-woven fabric as a supporting layer of a water treatment membrane, a method for preparing the wet non-woven fabric, and a water treatment membrane containing the wet non-woven fabric. The wet non-woven fabric has an average pore size of no greater than 20 .Math.m, a maximum pore size of no greater than 40 .Math.m, and a maximum pore size/average pore size ratio of no less than 1 and no greater than 12.

A list of highly suitable textiles and a method to combine them into a durable reusable filtration medium with high particles filtration efficiency (PFE) and breathability that lasts over 50-75 laundering cycles. Filtration medium achieves PFE only through mechanical means, without fragile and harmful physicochemical pre-treatments. Different textiles are assembled considering their individual breathability and their complementary in terms of PFE on different particles' sizes to achieve good breathability and high PFE on a large range (20 nm-4 μm) after many laundering cycles, or several layers of the same textile are paired, while varying the fibers' orientation and dimensions in each layer to increase efficiency. This assembling method highly improves PFE, service life and performances' stability of the filtration medium by addressing structural weaknesses linked to anisotropy in each layer, and by protecting their fine fibers from mechanical wear and clogging through a face-to-face closed filtration cell-type pairing.

A method for producing a fibrous web includes: (a) a fibrous ply containing polylactide fibers and, as necessary, other fibers are laid on a substrate in a random fiber arrangement, (b) initially a loose, pre-compressed nonwoven is created by applying a first pressure to the fibrous ply, the tear resistance of which nonwoven permits free bridging of a span between 0.1 m and 1 m before the nonwoven tears, (c) the pre-compressed nonwoven is then passed through the calender gap, wherein a pattern consisting of point or linear pressure zones is formed in the gap, with the fibers in the pressure zones being exposed to a second pressure, which is higher than the first pressure, and to a temperature such that the fibers fuse.

The present disclosure is directed toward an improved nanofibrous electret filtration media of which the stand-alone electret nanofibrous web comprises a single source randomly intermingled fiber network that yields high breathability due to the high porosity and improved filtration efficiency for use as improved filtration media for respiratory devices and face masks.

An AM/AV fabric comprising base fibers comprising a base polymer composition and AM/AV fibers comprising an AM/AV polymer composition comprising an AM/AV polymer and an AM/AV compound. The base fibers and the AM/AV fibers are intermingled with one another; and the fabric demonstrates an Escherichia coli efficacy log reduction greater than 4.0, as measured in accordance with ASTM E3160 (2018) and a particle filtration efficiency greater than 35%.

Nonwoven fabrics are provided that include (i) a plurality of continuous matrix fibers comprising a first polymeric material having a first melting point and including a first polymer component, in which the first polymer component comprises a first recycled-polyester, and (ii) a plurality of binder fibers having an irregular cross-section randomly dispersed throughout the plurality of matrix fibers, in which the plurality of binder fibers comprising a second polymeric material having a second melting point including a second polymer component. The second melting point being less than the first melting point.

A long-life in filters is required as filter members for slurry liquid having high-viscosity and high-solid-content ratio. It is provided to solve the problem, the filter element for filtering slurry liquid, wherein nets and non-woven fabrics are alternately layered, wherein each of the nets has first fibers parallelly extending in one direction and second fibers parallelly extending in a direction angled to the one direction and contacting sides of the first fibers, wherein the first and second fibers forms mesh-pores at portions surrounded by the first and second fibers, wherein each of the non-woven fabrics has protrusions on surfaces of the each of the non-woven fabrics in a thickness-direction, the protrusions formed to repeatedly come out on the surfaces of the each of the non-woven fabrics in a surface-direction of the each of the non-woven fabrics.

A non-woven electret fibrous web for electrostatic adsorption and odor elimination and the preparation process thereof. In certain exemplary embodiments, the non-woven electret fibrous web includes a multiplicity of electret fibers, at least one of a plurality of photo-catalytic fibers or a plurality of multi-component fibers; and optionally, at least one of a plurality of chemically-active particulates, a plurality of carbon-based fibers, or a plurality of mono-component thermoplastic fibers. In other exemplary embodiments, carding and cross-lapping or air-laying processes are disclosed for making nonwoven fibrous webs including electret fibers and one or more of photocatalytic fibers, chemically-active particulates, multi-component fibers, mono-component thermoplastic fibers, or carbon-based fibers. In some exemplary embodiments, exemplary non-woven electret fibrous webs of the disclosure exhibit superior gas permeation characteristics, high adsorption characteristics for airborne contaminants, as well as an odor elimination function.