Filter media comprising non-woven fiber webs having one or more advantageous physical properties are generally described. In some embodiments, a filter media and/or non-woven fiber web described herein comprises a combination of fibers that results in enhanced physical properties. For example, the non-woven fiber web may comprise a combination of fiber types that is advantageous, such as a combination comprising fibrillated fibers, glass fibers, and/or binder fibers. In some cases, the filter media and/or non-woven fiber web comprising the combination of fibers may be formed into undulations (e.g., by a creping and/or microcreping process) to further enhance the physical properties of the filter media and/or non-woven fiber.

Filter media are described. In particular, a filter media includes an intake side, an exhaust side, and a plurality of fibers distributed throughout the filter media. The fibers have a plurality of deniers, and fibers disposed proximate the intake side have a first denier and fibers disposed proximate the exhaust side have a second denier. The first denier is larger than the second denier.

A method for filtering airborne particulates is described. The method includes providing an exhaust hood, and the exhaust hood defines an intake and the exhaust hood being adapted to receive airborne particulates via the intake. The method also includes conveying a portion of a filter media from a media source area to an active media area, transferring the portion of the filter media from the active media area to a media discard area, the media discard area and the media source area being disposed on substantially opposed sides of the active media area, and severing the portion of the filter media in the media discard area from a remainder of the filter media.

This invention concerns ultra-high purity, ultra-high performance biogenic silica filtration products comprising diatomaceous earth. In particular, it relates to products comprising diatomaceous earth which is derived from ores that have been specifically selected for their naturally low centrifuged wet density and which have been intensively beneficiated to reduce extractable impurities to near or below detection limits. The low centrifuged wet density of the selected natural ore is either maintained or further reduced through the beneficiation process, which provides for filtration product/media with high particulate holding capacities able to provide for extended filtration cycle times.

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.

In a method of treating a gas stream (32) containing combustible and/or reactive particles (34) at least a part of the particles (34) contained in the gas stream (32) is separated from the gas stream (32) by means of a separation device (36). The particles (34) separated from the gas stream (32) by means of the separation device (36) are supplied to a collecting vessel (40). The supply of particles (34) to the collecting vessel (40) is interrupted. A flame retardant material (57) is supplied to the collecting vessel (40) so as to form a cover layer of flame retardant material (57) on the particles (34) contained in the collecting vessel (40).

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.

A material comprising unique nanofiber layers, and more particularly, this invention relates to a method for creating a material that is made from multiple unique nanofiber layers that can be utilized as filter media among other applications. The nanofiber layers have a plurality of fine fibers with an average diameter of less than 1 micron. In embodiments, the fine fibers are formed from a polymer. The material can be created according to a method in which the fine fiber strands are formed from a polymer melt or a polymer solution. The fine fibers can then be layered on top of one another to form materials such as filter media.

An improved stretchable filtration fabric laminate is provided. The laminate includes a first fabric layer and a nanofiber layer. The laminate may be stretched without damaging the laminate. The laminate is thus suitable for incorporation into wearable protective garments, such as protective hoods, balaclavas, scarves, etc. that provide both protection and air filtration to the wearer.

A filtration material of the present invention comprises a bulky fiber sheet layer having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer in which two or more types of fibers different in constituent resin are mixed, wherein constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layer. A three-layer filtration material of the present invention comprises bulky fiber sheet layers having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer, which is located between the bulky fiber sheet layers, wherein the constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layers, and both bulky fiber sheet layers contain fibers having a limiting oxygen index of 20 or more, and have a mass per unit area 0.5 times or more than that of the triboelectrically-charged nonwoven fabric layer. A filter element of the present invention comprises the filtration material in a pleated state.