# US 5,705,444 A · Filter material of ceramic oxide fibers and vermiculite particles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,705,444 A - Document ID: US5705444A - Status: Granted - Kind: A - Application number: 08/670,462 - Filed: 1996-06-26 - Granted: 1998-01-06 - Earliest claimed: 1996-05-06 - Assignees: Minnesota Mining and Manufacturing Company - Inventors: Thomas L. Tompkins; Edward M. Fischer; Timothy J. Gennrich; Steven R. Paulson - Web page: https://patentgrep.com/patent/US5705444A ## CPC - C04B 41/009: {characterised by the material treated} - B01D 39/2017: {the material being filamentary or fibrous} - B01D 39/2072: {the material being particulate or granular} - B01D 39/2082: {the material being filamentary or fibrous} - C03C 13/00: Fibre or filament compositions (manufacture of fibres or filaments C03B37/00) - C03C 25/47: containing particles, fibres or flakes, e.g. in a continuous phase - C04B 30/02: containing fibrous materials - C04B 41/5024: {Silicates (C04B41/5022 takes precedence; silico-fluorides C04B41/5018)} - C04B 2111/00793: {as filters or diaphragms} - Y10T 442/2139: Coating or impregnation specified as porous or permeable to a specific substance [e.g., water vapor, air, etc.] - Y10T 442/2369: Coating or impregnation improves elasticity, bendability, resiliency, flexibility, or shape retention of the fabric - Y10T 442/3878: Fluorinated olefin polymer or copolymer sheet or film [e.g., Teflon@, etc.] - Y10T 442/699: Including particulate material other than strand or fiber material - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - 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) - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Filter material comprising fabric of ceramic oxide fibers and vermiculite particulate is disclosed. The presence of the vermiculite provides an improvement in the flexural endurance of the fabric. ## Claims ### Claim 1 A filter material comprising fabric of ceramic oxide fibers and vermiculite particulate, said fibers collectively having an outer surface, at least a portion of said outer surface being covered by a sufficient amount of vermiculite particulate such that said filter material has an increased flexural endurance over the fabric without the presence of said vermiculite of at least 100 percent, said filter material having a gas permeability of at least 0.15 l/min/cm.sup.2. ### Claim 2 (depends on 1) The filter material according to claim 1 wherein said fabric comprises at least 75 percent by volume of said ceramic oxide fiber, based on the total fiber volume of said fabric. ### Claim 3 (depends on 2) The filter material according to claim 2 wherein said filter material has an increased flexure endurance over the fabric without the presence of said vermiculite of at least 200 percent. ### Claim 4 (depends on 3) The filter material according to claim 3 wherein said filter material has an increased flexure endurance over the fabric without the presence of said vermiculite of at least 500 percent. ### Claim 5 (depends on 4) The filter material according to claim 4 having a gas permeability of at least 0.3l/min/cm.sup.2. ### Claim 6 (depends on 5) The filter material according to claim 5 having a gas permeability of less than 1.5 l/min/cm.sup.2. ### Claim 7 (depends on 5) The filter material according to claim 5 having a gas permeability of less than 0.8 l/min/cm.sup.2. ### Claim 8 (depends on 5) The filter material according to claim 5 having a gas permeability in the range from 0.3 to 2 l/min/cm.sup.2. ### Claim 9 (depends on 5) The filter material according to claim 5 having a gas permeability in the range from 0.3 to 0.8 l/min/cm.sup.2. ### Claim 10 (depends on 5) The filter material according to claim 5 wherein the vermiculite particulate have lengths and widths each in the range from about 0.3 micrometer to about 100 micrometers, and thicknesses ranging from about 10.degree. A to about 4200.degree. A. ### Claim 11 (depends on 5) The filter material according to claim 5 wherein said ceramic oxide fibers are selected from the group consisting of glass fibers, alpha alumina fibers, aluminosilicate fibers, zirconia fibers, and combinations thereof. ### Claim 12 (depends on 5) The filter material according to claim 5 wherein said ceramic oxide fibers are aluminoborosilicate fibers. ### Claim 13 (depends on 5) The filter material according to claim 5 wherein said ceramic oxide fibers are crystalline ceramic oxide fibers. ### Claim 14 (depends on 5) The filter material according to claim 5 wherein said ceramic oxide fibers are glass fibers. ### Claim 15 (depends on 14) The filter material according to claim 14 wherein said glass fibers comprise by weight, on a theoretical oxide basis, SiO.sub.2 in the range from about 64 to about 66 percent, Al.sub.2 O.sub.3 in the range from about 24 to about 26 percent, MgO in the range from about 9 to about 11 percent, based on the total oxide content of said fibers. ### Claim 16 (depends on 15) The filter material according to claim 15 wherein said glass fibers are made of glass having a softening point of about 860.degree. C. ### Claim 17 (depends on 14) The filter material according to claim 14 wherein said glass fibers comprise by weight, on a theoretical oxide basis, SiO.sub.2 in the range from about 52 to about 56 percent, Al.sub.2 O.sub.3 in the range from about 12 to about 16 percent, CaO in the range from about 16 to about 25 percent, up to about 5 percent MgO, B.sub.2 O.sub.3 in the range from about 5 to about 10 percent, based on the total oxide content of said fibers. ### Claim 18 (depends on 14) The filter material according to claim 14 wherein said glass fibers are made of glass having a softening point in the range from about 600.degree. C. to about 875.degree. C. ### Claim 19 (depends on 5) The filter material according to claim 5 wherein said fabric is woven. ### Claim 20 (depends on 5) A filter bag comprising filter material according to claim 5. ### Claim 21 (depends on 2) The filter material according to claim 2 wherein said filter material has an increased flexure endurance over the fabric without the presence of said vermiculite of at least 1000 percent. ### Claim 22 (depends on 2) The filter material according to claim 2 wherein said filter material has an increased flexure endurance over the fabric without the presence of said vermiculite of at least 5000 percent.