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.

Articles and methods involving filter media are generally provided. In certain embodiments, the filter media includes at least a first layer, a second layer, and an adhesive resin positioned between the first layer and the second layer. In some embodiments, the first layer may be a pre-filter layer or a support layer. The second layer may, for example, comprise fibers formed by a solution spinning process and/or may comprise fine fibers. In some embodiments, the adhesive resin may be present in a relatively low amount and/or may have a low glass transition temperature. The filter media as a whole may have one or more advantageous properties, including one or more of a high stiffness, a high bond strength between the first layer and the second layer, a high gamma, and/or a low increase in air resistance after being subjected to an IPA vapor discharge. The filter media may be, for example, a HEPA filter and/or an ULPA filter.

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.

This disclosure relates to the use of a hydrophobic hollow fiber filter for the filtration of cell cultures and other biological perfusions, due to its resistance to fouling, as well as the ability to filter solutions with a high solid content. A hydrophobic hollow fiber filter may be used within a filter housing in conjunction with a process vessel and a traditional separation system. When the system is used with alternating tangential flow or tangential flow filtration, the hydrophobic hollow fiber filter results in more effective filtration of the filtrate, leading to greater concentration of the retentate, even in solution containing high levels of solids.

The prevent invention addresses the problem of providing a filter cloth for a bag filter, which has excellent collection efficiency, has excellent collection efficiency, provides low pressure drop and is resistant to clogging, and also has excellent dust-off ability; a method for producing the same; and a bag filter. As a means for resolution, a nonwoven fabric containing an ultrafine fiber having a fiber diameter D of 200 to 2,000 nm is laminated on a base material to form a filter cloth for a bag filter.

High efficiency and high capacity glass-free filtration media include a blend of synthetic non-fibrillated staple fibers and fibrillated cellulosic staple fibers, wherein the fibrillated cellulosic fibers are present in the media in an amount to achieve a multipass dust holding capacity of 10 mg/in.sup.2 and greater, and a multipass filtration efficiency at 1.5 microns of greater than 50%. The filtration media is made by forming a wet laid sheet from a fibrous slurry blend of the synthetic non-fibrillated staple fibers and fibrillated cellulosic staple fibers, followed by drying the sheet to obtain the filtration media. Optionally, the filtration media may be provided with a resin binder and may be grooved and/or pleated.

A face mask containing a network of conductive activated carbon meso-fibers crosslinked with a crosslinking agent bonded to a insulative polymeric micro-fiber based purification element. The purification element is captured between two ridged porous elements and contacted to the face by a biocompatible flexible polymeric seal. Optionally the front cover attaches to a main frame of the mask through a system of sliding locks that are coupled with bayonet latch mechanisms. The face mask attaches to the head of a wearer through a harness that couples with the sliding locks or alternatively with a biocompatible adhesive.

A sintered metal object comprises metal fibers in a nonwoven web arrangement. The metal fibers comprise stainless steel fibers having a duplex microstructure. The duplex microstructure is a mixed microstructure of austenite and ferrite. The stainless steel fibers are bonded at at least part of their contacting points by means of sinter bonds.

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.

A biodegradable cigarette filter tow includes a mixture of at least two or more natural materials selected from the group consisting of hemp fiber, flax fiber, abaca fiber or pulp, sisal fiber or pulp, wood pulp, and cotton fiber or cotton flock. The mixture may also include regenerated cellulose fibers. The mixture may include a natural binder or may be hydroentangled.