# US 2014/0360146 A1 · Wet-laid dual-layer air filtration media including a large diameter synthetic polymeric fiber in a top layer thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0360146 A1 - Document ID: US20140360146A1 - Status: Published application - Kind: A1 - Application number: 14/299,388 - Filed: 2014-06-09 - Published: 2014-12-11 - Earliest claimed: 2013-06-10 - Assignees: Lydall, Inc. - Applicants: Lydall, Inc. - Inventors: William H. Cambo; Stephen Edward Gross - Web page: https://patentgrep.com/patent/US20140360146A1 ## CPC - B01D 39/1623: {of synthetic origin} - B01D 46/0001: {Making filtering elements} - B01D 46/521: {using folded, pleated material} - B01D 2239/065: More than one layer present in the filtering material - B01D 2239/1233: Fibre diameter - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract A wet-laid dual-layer air filtration media having a thin, lightweight top layer and a bottom layer is provided. The novel media includes a large diameter synthetic polymeric fiber in the top layer that deforms plastically and retains cohesion as a single object, while minimizing use of frangible components that become airborne upon handling. The novel media provides improved high dust holding capacity, while typically maintaining an overall lower basis weight than heretofore available media. ## Claims ### Claim 1 A wet-laid dual-layer gas filtration media, comprising: a top layer, said top layer comprising about 2-100 wt. % synthetic polymeric fiber, wherein the synthetic polymeric fiber is a polymer material that deforms plastically and retains cohesion as a single object, and wherein the diameter of the synthetic polymeric fiber is about 6-50 microns; and a bottom layer, wherein the media has a basis weight of about 38-50 lbs./3000 ft2 and a dust holding capacity of at least about 34 g/m2 at about a 38% DOP penetration, the top layer has a basis weight of about 5-20% of the media basis weight and is configured with minimal frangible components that become airborne upon handling. ### Claim 2 (depends on 1) The media of claim 1, wherein the synthetic polymeric fiber comprises at least one of bicomponent fibers, shaped fibers, crimped fibers and hollow fibers. ### Claim 3 (depends on 1) The media of claim 1, wherein the diameter of the synthetic polymeric fiber is at least about 15.9-50 microns. ### Claim 4 (depends on 1) The media of claim 1, wherein the synthetic polymeric fiber is selected from the group comprising polyester, nylon, acrylic, modacrylic, polyolefin, or combinations thereof. ### Claim 5 (depends on 1) The media of claim 1, further comprising a semi-synthetic polymeric fiber, such as rayon. ### Claim 6 (depends on 1) The media of claim 1, wherein the top layer comprises about 10-90 wt. % synthetic polymeric fiber. ### Claim 7 (depends on 1) The media of claim 1, wherein the synthetic polymeric fiber is selected from the group comprising polylactide (PLA), polyethylene, polypropylene, polyethylene terephthalate, or combinations thereof. ### Claim 7 (depends on 1) The media of claim 1, wherein the top layer has a low tendency to shed fibers. ### Claim 8 (depends on 1) The media of claim 1, wherein the media has a MERV rating of at least about 11-15. ### Claim 9 (depends on 1) The media of claim 1, wherein the synthetic polymeric fiber is a low melt sheath/core bicomponent fiber. ### Claim 10 (depends on 9) The media of claim 9, wherein the low melt sheath/core bicomponent fiber provides a tie down affect to fibers of the top layer. ### Claim 11 (depends on 1) The media of claim 1, wherein the media has a basis weight of about 40-44 lbs./3000 ft2. ### Claim 12 (depends on 1) The media of claim 1, wherein the media has a total thickness of at least about 14 mils and the top layer has a thickness of less than about 30% of the media thickness. ### Claim 13 (depends on 1) The media of claim 1, wherein the composition of the bottom layer is not the same as the composition of the top layer. ### Claim 14 (depends on 1) A pleated assembly comprising the media of claim 1. ### Claim 15 A wet-laid dual-layer gas filtration media, comprising: a top layer, said top layer comprising synthetic polymeric fiber, wherein the synthetic polymeric fiber is a polymer material that deforms plastically and retains cohesion as a single object, and wherein the diameter of the synthetic polymeric fiber is about 6-50 microns; and a bottom layer, wherein the media has a basis weight of about 38-50 lbs./3000 ft2 and a dust holding capacity of at least about 34 g/m2 at about a 38% DOP Penetration, the top layer has a basis weight of about 1-20% of the media basis weight and is configured with minimal frangible components that become airborne upon handling, the media comprising sufficient non-synthetic polymeric fiber in the top layer to pass a flammability test. ### Claim 16 (depends on 1) A method of making the wet-laid dual-layer gas filtration media of claim 1, comprising: depositing the bottom layer onto a forming belt; depositing the top layer atop the bottom layer in a way that at least partially mixes the top and bottom layers to form a gradient interface layer between the top and bottom layer.