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 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.

A non-pleated depth filter element in the form of a tubular ring of depth filter media is provided. Multiple wraps of sheets, some including fine fibers, are employed. The depth filter element has particular applications to liquid filtration applications.

The present invention provides a novel nonwoven felt fabric, which is made of at least one low-melting-point short fiber and at least one high-melting-point short fiber of same type or different types, wherein the fabric is stiff enough to be self-sustaining and have the ability of shape maintenance. The felt fabric exhibits excellent pleatability, moldability and compressive strength. The invention also provides a method for producing the felt fabric, and a filter comprising the felt fabric used as the material of a filter medium of the filter, wherein the filter medium requires no support structure to stand alone and persistently retains its shape.

An air filter for automobiles includes, a main filter and a prefilter, wherein the prefilter comprises a nonwoven synthetic fiber having an average density of 0.01 to 0.5 g/cm.sup.3 and a moisture absorbent is adsorbed to the prefilter.

Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.

A humidification filter, in one aspect, includes at least one of natural fiber and regenerated fiber mixed with a hydrophobic synthetic fiber.

The present invention provides compositions comprising cellulose fibers and cellulose ester fibers and wet laid articles made from the compositions, as well as wet laid processes to produce these compositions. More specifically, the present invention provided compositions comprising cellulose fibers and cellulose acetate fibers and wet laid articles made from these compositions as well as wet laid processes to produce these compositions. The present invention also relates to developing a composition, process, wet laid product, or articles exhibiting any one of many the desired benefits. The present invention also relates to a filter media for air filtration comprising cellulose fiber and a staple fiber; wherein said staple filter comprises cellulose ester; wherein said air permeability is higher for a given mean pore size as compared to a filtration that comprises 100% cellulose.

It is an object of the present invention to provide a nonwoven fabric having mechanical strength which is hardly cut and broken by an external force, and a separator for electrochemical devices using the nonwoven fabric.

The inventive nonwoven fabric has a sum of tensile strengths by zero-span per basis weight in the machine direction and the cross-machine direction of 6.5N/50 mm or more. Thus, the strength of the constituent fibers of this nonwoven fabric against an external force is high, and this nonwoven fabric has mechanical strength which is hardly cut and broken by an external force.

The separator for electrochemical devices of the present invention is composed of this nonwoven fabric.

A macro electrically active mask includes two conductive layers separated by at least one filtering and insulating layer. The conductive layers are connected to each other by a power source. The power source includes an oscillator and a high voltage transformer. The power source generates a periodic voltage with a fundamental frequency and multiple harmonic frequencies. The power source is connected between the two conductive layers and the periodic voltage generates a periodic electric field between the two conductive layers. The fundamental frequency, the duty cycle, and the amplitude of the periodic voltage are configured to inactivate the microorganism that pass through the electric field.