Hollingsworth & Vose Company

Douglas M Guimond

Sudhakar Jaganathan

Carrie Liu

James M Witsch

John A Wertz

Maxim Silin

Nagendra Anantharamaiah

Mark A Gallimore

Gerald Gadbois

Mark Snyder

Xiaodan Zhang

Milind Godsay

Mark S Millar

David Vallery

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.

Filter media including adhesives and/or oleophobic properties

Filter media including adhesives

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.

Filter media including flame retardant fibers

Filter media are described. The filter media may include multiple layers. In some embodiments, the filter media include a nanofiber layer adhered to another layer. In some embodiments, the layer to which the nanofiber layer is adhered is formed of multiple fiber types (e.g., fibers that give rise to structures having different air permeabilities and/or pressure drops). In some embodiments, the nanofiber layer is adhered to a single-phase or a multi-phase layer. In some embodiments, the nanofiber layer is manufactured from a meltblown process. The filter media may be designed to have advantageous properties including, in some cases, a high dust particle capture efficiency and/or a high dust holding capacity.

Filter media with a multi-layer structure

Systems and methods for forming fiber webs, including those suitable for use as filter media and battery separators, are provided. In some embodiments, the systems and methods may involve the use of one or more fiber mixtures to form a fiber web. The fiber mixtures may flow in different portions of a system for forming a fiber web that may be separated by a lamella, and may join at a fiber web forming zone to produce a fiber web having multiple layers. The amount of mixing of the fiber mixtures at or near the fiber web forming zone may be controlled to produce fiber webs having different structural and/or performance characteristics. In some embodiments, the systems and methods described herein can be used to form fiber webs having a gradient in a property across a portion of, or the entire, thickness of the fiber web.

Systems and methods for making fiber webs

The fiber webs described herein may be incorporated into filter media and filter elements. The fiber webs may exhibit a high dust holding capacity. The fiber webs may also exhibit a low thickness. The fiber webs may be sufficiently flexible and/or deformable so that they may be processed to include a series of waves (also known as flutes) that extend along the cross-machine direction.

Flutable fiber webs with high dust holding capacity

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Pepperell, MA, United States of America

Douglas M Guimond