# US 2014/0196421 A1 · Urea filter material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196421 A1 - Document ID: US20140196421A1 - Status: Published application - Kind: A1 - Application number: 13/983,332 - Filed: 2012-02-02 - Published: 2014-07-17 - Earliest claimed: 2011-02-03 - Assignees: Carl Freudenberg KG; Mahle International GmbH - Inventors: Stefan Jauss; Sven Siegle; Anette Arnold; Thomas Kuehlwein; Holger Leubner - Web page: https://patentgrep.com/patent/US20140196421A1 ## CPC - B01D 39/1623: {of synthetic origin} - B01D 46/14: arranged in a star shape - B32B 5/02: characterised by structural features of a {fibrous or filamentary} layer {(layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02)} - F01N 3/2066: {Selective catalytic reduction [SCR]} - B01D 2239/065: More than one layer present in the filtering material - B01D 2239/0654: Support layers - B01D 2239/0677: by spot-welding - B32B 2250/03: 3 layers - B32B 2250/20: All layers being fibrous or filamentary - B32B 2262/0253: Polyolefin fibres - F01N 2610/02: the substance being ammonia or urea - F01N 2610/1426: Filtration means - Y02T 10/12: Improving ICE efficiencies - 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) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A urea filter material may have a base layer, a cover layer and a filter layer arranged between the base layer and the cover layer, wherein all of the layers are formed from polypropylene non-woven fabric. ## Claims ### Claim 1 A urea filter material for a urea filter, comprising: a base layer, a cover layer and a filter layer arranged between the base layer and the cover layer, wherein all of the layers are formed from polypropylene non-woven fabric. ### Claim 2 (depends on 1) The urea filter material according to claim 1, wherein at least the base layer and the filter layer are welded together. ### Claim 3 (depends on 1) The urea filter material according to claim 1, wherein at least the filter layer and the cover layer are stamped together. ### Claim 4 (depends on 1) The urea filter material according to claim 1, wherein the layers differ from each other in at least one of thicknesses, strengths and filter properties. ### Claim 5 (depends on 1) The urea filter material according to claim 1, wherein the layers include fibres of varying thickness and length. ### Claim 6 A urea filter element comprising: a urea filter material having a base layer, a cover layer and a filter layer arranged between the base layer and the cover layer, wherein all of the layers are formed from polypropylene non-woven fabric. ### Claim 7 (depends on 6) The urea filter element according to claim 6, wherein the urea filter element is configured as an annular filter element and the urea filter material forms a pleated star, and further comprising a first and a second end disk arranged at opposite ends of the filter material, wherein the end disks are made of polypropylene. ### Claim 8 (depends on 6) The urea filter element according to claim 6, wherein at least the base layer and the filter layer are welded together. ### Claim 9 (depends on 8) The urea filter element according to claim 8, wherein at least the base layer and the filter layer are welded via ultrasonic welding. ### Claim 10 (depends on 6) The urea filter element according to claim 6, wherein at least the filter layer and the cover layer are stamped together. ### Claim 11 (depends on 10) The urea filter element according to claim 10, wherein at least the filter layer and the cover layer are stamped together via thermal rolling. ### Claim 12 (depends on 6) The urea filter element according to claim 6, wherein the layers differ from each other in at least one of thicknesses, strengths and filter properties. ### Claim 13 (depends on 6) The urea filter element according to claim 6, wherein the layers include fibres of varying thickness and length. ### Claim 14 (depends on 2) The urea filter material according to claim 2, wherein at least the base layer and the filter layer are welded together via ultrasonic welding. ### Claim 15 (depends on 2) The urea filter material according to claim 2, wherein the layers differ from each other in at least one of thicknesses, strengths and filter properties. ### Claim 16 (depends on 2) The urea filter element according to claim 2, wherein the layers include fibres of varying thickness and length. ### Claim 17 (depends on 3) The urea filter material according to claim 3, wherein at least the filter layer and the cover layer are stamped together via thermal rolling. ### Claim 18 (depends on 3) The urea filter material according to claim 3, wherein the layers differ from each other in at least one of thicknesses, strengths and filter properties. ### Claim 19 (depends on 3) The urea filter element according to claim 3, wherein the layers include fibres of varying thickness and length. ### Claim 20 (depends on 4) The urea filter element according to claim 4, wherein the layers include fibres of varying thickness and length.