Particle-containing fibrous web

Abstract

A porous sheet article including a self-supporting nonwoven web of less than 20 weight percent polymeric fibers exhibiting no more than about 1 weight percent dimethyl methyl phosphonate uptake and at least 80 weight percent sorbent particles enmeshed in the web, the sorbent particles being sufficiently evenly distributed in the web and the fiber polymer(s) being such that the web has an Adsorption Factor A of at least 1.6x10<4> / mm water. The articles have low pressure drop and can provide filter elements and other individual or collective protection devices having long service lives and an Adsorption Factor approaching and in some instances exceeding that of a packed carbon bed.

Description

[0001] Cross references to related patent applications

[0002] This patent application is a continuation-in-part of co-pending patent application Ser. No. 10 / 983,770, filed November 8, 2004, the entire disclosure of which is incorporated herein by reference. technical field

[0003] The present invention relates to fiber webs containing particles and filter devices. Background technique

[0004] Respirators used in the presence of solvents and other hazardous airborne substances sometimes employ filter elements that contain sorbent particles. The filter element may be a filter cartridge comprising a bed of sorbent particles, or a layer or insert of filter material impregnated or coated with sorbent particles. The design of a filter element can involve balancing sometimes conflicting factors such as pressure drop, shock resistance, overall service life, weight, thickness, overall size, resistance to potentially damaging forces such as vibration or wear Force and sample-to...

Images