CA2168126C - Method of charging electret filter media - Google Patents
Method of charging electret filter media Download PDFInfo
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- CA2168126C CA2168126C CA002168126A CA2168126A CA2168126C CA 2168126 C CA2168126 C CA 2168126C CA 002168126 A CA002168126 A CA 002168126A CA 2168126 A CA2168126 A CA 2168126A CA 2168126 C CA2168126 C CA 2168126C
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- water
- microfibers
- pentene
- poly
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
- D06M11/01—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with hydrogen, water or heavy water; with hydrides of metals or complexes thereof; with boranes, diboranes, silanes, disilanes, phosphines, diphosphines, stibines, distibines, arsines, or diarsines or complexes thereof
- D06M11/05—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with hydrogen, water or heavy water; with hydrides of metals or complexes thereof; with boranes, diboranes, silanes, disilanes, phosphines, diphosphines, stibines, distibines, arsines, or diarsines or complexes thereof with water, e.g. steam; with heavy water
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/08—Filter cloth, i.e. woven, knitted or interlaced material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/14—Other self-supporting filtering material ; Other filtering material
- B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
- B01D39/1607—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
- B01D39/1623—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/407—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties containing absorbing substances, e.g. activated carbon
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
- D04H1/4282—Addition polymers
- D04H1/4291—Olefin series
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
- D04H1/4382—Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
- D04H1/43825—Composite fibres
- D04H1/43828—Composite fibres sheath-core
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
- D04H1/4382—Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
- D04H1/43835—Mixed fibres, e.g. at least two chemically different fibres or fibre blends
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
- D04H1/4382—Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
- D04H1/43838—Ultrafine fibres, e.g. microfibres
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/44—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling
- D04H1/46—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
- D04H1/492—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres by fluid jet
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
- D04H1/56—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving in association with fibre formation, e.g. immediately following extrusion of staple fibres
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M10/00—Physical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. ultrasonic, corona discharge, irradiation, electric currents, or magnetic fields; Physical treatment combined with treatment with chemical compounds or elements
- D06M10/02—Physical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. ultrasonic, corona discharge, irradiation, electric currents, or magnetic fields; Physical treatment combined with treatment with chemical compounds or elements ultrasonic or sonic; Corona discharge
- D06M10/025—Corona discharge or low temperature plasma
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- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B23/00—Filters for breathing-protection purposes
- A62B23/02—Filters for breathing-protection purposes for respirators
- A62B23/025—Filters for breathing-protection purposes for respirators the filter having substantially the shape of a mask
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/02—Types of fibres, filaments or particles, self-supporting or supported materials
- B01D2239/0216—Bicomponent or multicomponent fibres
- B01D2239/0225—Side-by-side
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D2239/02—Types of fibres, filaments or particles, self-supporting or supported materials
- B01D2239/0216—Bicomponent or multicomponent fibres
- B01D2239/0233—Island-in-sea
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/04—Additives and treatments of the filtering material
- B01D2239/0407—Additives and treatments of the filtering material comprising particulate additives, e.g. adsorbents
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/04—Additives and treatments of the filtering material
- B01D2239/0435—Electret
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/0604—Arrangement of the fibres in the filtering material
- B01D2239/0618—Non-woven
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/0604—Arrangement of the fibres in the filtering material
- B01D2239/0622—Melt-blown
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/0604—Arrangement of the fibres in the filtering material
- B01D2239/064—The fibres being mixed
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/065—More than one layer present in the filtering material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/065—More than one layer present in the filtering material
- B01D2239/0654—Support layers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/065—More than one layer present in the filtering material
- B01D2239/0663—The layers being joined by hydro-entangling
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/069—Special geometry of layers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D2239/10—Filtering material manufacturing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D2239/12—Special parameters characterising the filtering material
- B01D2239/1233—Fibre diameter
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/12—Special parameters characterising the filtering material
- B01D2239/1291—Other parameters
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M2101/00—Chemical constitution of the fibres, threads, yarns, fabrics or fibrous goods made from such materials, to be treated
- D06M2101/16—Synthetic fibres, other than mineral fibres
- D06M2101/18—Synthetic fibres consisting of macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
- Y10S264/48—Processes of making filters
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S55/00—Gas separation
- Y10S55/05—Methods of making filter
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S55/00—Gas separation
- Y10S55/35—Respirators and register filters
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S55/00—Gas separation
- Y10S55/39—Electrets separator
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
- Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
- Y10T442/608—Including strand or fiber material which is of specific structural definition
- Y10T442/614—Strand or fiber material specified as having microdimensions [i.e., microfiber]
- Y10T442/626—Microfiber is synthetic polymer
Abstract
A method of charging a nonwoven web of thermoplastic microfibers to provide electret filter media is provided. The method includes impinging on a nonwoven web of thermoplastic nonconductive microfibers capable of having a high quantity of trapped charge jets of water or a stream of water droplets at a pressure sufficient to provide the web with filtration enhancing electret charge and drying said web.
Description
WO 95/05501 PCTlUS94/09275 METHOD OF CHARGING ELECTRET FILTER MEDIA
FIELD OF THE INVENTION
The invention concerns electret-enhanced filter media (more simply called "electret filters") made of fibers such as melt-blown microfibers. The invention concerns an improved method for making fibrous electret filters for removing particulate matter from air. The invention is especially concerned with respirators and improving the level of filtration-enhancing electrostatic charges on the filter media.
DESCRIPTION OF THE RELATED ART
For many years nonwoven fibrous filter webs have been made from polypropylene using melt-blowing apparatus of the type described in Report No.
4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Super Fine Organic Fibers" by Van A. Wente et al. Such melt-blown microfiber webs continue to be in widespread use for filtering particulate contaminants, e.g., as face masks and as water filters, and for other purposes, e.g., as a sorbent web to remove oil from water, acoustic insulation and thermal insulation.
FIELD OF THE INVENTION
The invention concerns electret-enhanced filter media (more simply called "electret filters") made of fibers such as melt-blown microfibers. The invention concerns an improved method for making fibrous electret filters for removing particulate matter from air. The invention is especially concerned with respirators and improving the level of filtration-enhancing electrostatic charges on the filter media.
DESCRIPTION OF THE RELATED ART
For many years nonwoven fibrous filter webs have been made from polypropylene using melt-blowing apparatus of the type described in Report No.
4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Super Fine Organic Fibers" by Van A. Wente et al. Such melt-blown microfiber webs continue to be in widespread use for filtering particulate contaminants, e.g., as face masks and as water filters, and for other purposes, e.g., as a sorbent web to remove oil from water, acoustic insulation and thermal insulation.
2 o The filtration quality of a melt-blown microfiber web can be improved by a factor of two or more when the melt-blown fibers are bombarded as they issue from the die orifices with electrically charged particles such as electrons or ions, thus making the fibrous web an electret. Similarly, the web can be made an electret by exposure to a corona after it is collected. Melt-blown 2 5 polypropylene microfibers are especially useful, while other polymers may also be used such as polycarbonates and polyhalocarbons that may be melt-blown and have appropriate volume-resistivities under expected environmental conditions.
Fibrous filters for removing particulate contaminants from the air are 3 0 also made from fibrillated polypropylene films. Electret filtration enhancement can be provided by electrostatically charging the film before it is fibrillated.
Common polymers such as polyesters, polycarbonates, etc. can be treated to produce highly charged electrets but these charges are usually short-lived especially under humid conditions. The electret structures may be films or sheets which find applications as the electrostatic element in electro-acoustic devices such as microphones, headphones and speakers, in dust particle control, high voltage electrostatic generators, electrostatic recorders and other applications.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a method of charging a nonwoven web comprising thermoplastic microfibers to provide electret filter media comprising the following steps: a) impinging on a nonwoven web of thermoplastic nonconductive microfibers, which have a resistivity greater than 1014 ohm-cm and are capable of having a high quantity of trapped charge, jets of water or a stream of water droplets at a pressure sufficient to provide the web with filtration enhancing electret charge and b) drying said web.
Surprisingly, it has been found that merely by impinging these jets of water or stream of water droplets onto the nonwoven microfiber web, the web develops filtration enhancing electret charge. The charging can be further enhanced by subjecting the web to corona discharge treatment prior to impingement by the water. Preferably, the web is formed from melt blown polypropylene microfibers, poly(4-methyl-1-pentene) microfibers or blends thereof. The term "hydrocharging" will be used herein to describe this method.
The webs appear to be charged after impingement by jets of water or a stream of water droplets because when a hydrocharged web is exposed to unfiltered x-ray radiation, the filtration efficiency is markedly reduced.
The fibrous electret filter produced by the method of the present invention is especially useful as an air filter element of a respirator such as a face mask or for such purposes as home and industrial air-conditioners, air cleaners, vacuum cleaners, medical air line filters, and air conditioning systems for vehicles and common equipment such as computers, computer disk drives and electronic equipment.
In respirator uses, the electret filters may be in the -2a-form of molded or folded half face masks, replaceable cartridges or canisters, or prefilters. In such uses, an air filter element produced by the method of the invention is surprisingly effective for removing particulate aerosols. When used as an air filter, such as in a respirator, the electret filter media has surprisingly better filtration performance than does a comparable electret filter charged by known methods.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an apparatus useful in making the nonwoven 1 o microfiber web used in the method of the present invention.
FIG. 2 is a perspective view of a water jet spray apparatus useful in the present invention.
FIG. 3 is a perspective view of a nebulizer useful in the present invention.
FIG. 4 is a perspective view of a pump action sprayer useful in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The melt blown microfibers useful in the present invention can be 2 o prepared as described in Van A. Wente, "Superfine Thermoplastic Fibers,"
Industrial En in~eerin;a Chemistry, vol. 48, pp. 1342-1346 and in Report No.
4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Super Fine Organic Fibers" by Van A. Wente et al.
The resin used to form the melt blown microfibers is a thermoplastic 2 5 nonconductive, i. e. , having a resistivity greater than 10'4 ohm ~ cm, resin capable of having a high quantity of trapped charge. Preferred resins include polypropylene, poly(4-methyl-1-pentene) and blends thereof. The resin should be substantially free from materials such as antistatic agents which could increase the electrical conductivity or otherwise interfere with the ability of the 3 o fibers to accept and hold electrostatic charges. The melt blown microfibers can be of a single resin, formed of a resin blend, e.g., polypropylene and poly(4-WO 95/05501 PCTlUS94/0927 ~~ ~126y methyl-1-pentene), or formed of two resins in layered or core/sheath configurations. When polypropylene and poly(4-methyl-1-pentene) are used in layered or core/sheath configurations, the poly(4-methyl-1-pentene) is preferably on the outer surface. ' Blown microfibers for fibrous electret filters of the invention typically have an effective fiber diameter of from about 3 to 30 micrometers preferably from about 7 to 15 micrometers, as calculated according to the method set forth in Davies, C.N., "The Separation of Airborne Dust and Particles," Institution of Mechanical Engineers, London, Proceedings 1B, 1952.
to Staple fibers may also be present in the web. The presence of staple fibers generally provides a more lofty, less dense web than a web of only blown microfibers. Preferably, no more than about 90 weight percent staple fibers are present, more preferably no more than about 70 weight percent.
Such webs containing staple fiber are disclosed in U.S. Pat. No. 4,118,531 (Hauser).
Sorbent particulate material such as activated carbon or alumina may also be included in the web. Such particles may be present in amounts up to about 80 volume percent of the contents of the web. Such particle-loaded webs are described, for example, in U.S. Pat. No. 3,971,373 (Braun), U.S. Pat. No.
Fibrous filters for removing particulate contaminants from the air are 3 0 also made from fibrillated polypropylene films. Electret filtration enhancement can be provided by electrostatically charging the film before it is fibrillated.
Common polymers such as polyesters, polycarbonates, etc. can be treated to produce highly charged electrets but these charges are usually short-lived especially under humid conditions. The electret structures may be films or sheets which find applications as the electrostatic element in electro-acoustic devices such as microphones, headphones and speakers, in dust particle control, high voltage electrostatic generators, electrostatic recorders and other applications.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a method of charging a nonwoven web comprising thermoplastic microfibers to provide electret filter media comprising the following steps: a) impinging on a nonwoven web of thermoplastic nonconductive microfibers, which have a resistivity greater than 1014 ohm-cm and are capable of having a high quantity of trapped charge, jets of water or a stream of water droplets at a pressure sufficient to provide the web with filtration enhancing electret charge and b) drying said web.
Surprisingly, it has been found that merely by impinging these jets of water or stream of water droplets onto the nonwoven microfiber web, the web develops filtration enhancing electret charge. The charging can be further enhanced by subjecting the web to corona discharge treatment prior to impingement by the water. Preferably, the web is formed from melt blown polypropylene microfibers, poly(4-methyl-1-pentene) microfibers or blends thereof. The term "hydrocharging" will be used herein to describe this method.
The webs appear to be charged after impingement by jets of water or a stream of water droplets because when a hydrocharged web is exposed to unfiltered x-ray radiation, the filtration efficiency is markedly reduced.
The fibrous electret filter produced by the method of the present invention is especially useful as an air filter element of a respirator such as a face mask or for such purposes as home and industrial air-conditioners, air cleaners, vacuum cleaners, medical air line filters, and air conditioning systems for vehicles and common equipment such as computers, computer disk drives and electronic equipment.
In respirator uses, the electret filters may be in the -2a-form of molded or folded half face masks, replaceable cartridges or canisters, or prefilters. In such uses, an air filter element produced by the method of the invention is surprisingly effective for removing particulate aerosols. When used as an air filter, such as in a respirator, the electret filter media has surprisingly better filtration performance than does a comparable electret filter charged by known methods.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an apparatus useful in making the nonwoven 1 o microfiber web used in the method of the present invention.
FIG. 2 is a perspective view of a water jet spray apparatus useful in the present invention.
FIG. 3 is a perspective view of a nebulizer useful in the present invention.
FIG. 4 is a perspective view of a pump action sprayer useful in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The melt blown microfibers useful in the present invention can be 2 o prepared as described in Van A. Wente, "Superfine Thermoplastic Fibers,"
Industrial En in~eerin;a Chemistry, vol. 48, pp. 1342-1346 and in Report No.
4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Super Fine Organic Fibers" by Van A. Wente et al.
The resin used to form the melt blown microfibers is a thermoplastic 2 5 nonconductive, i. e. , having a resistivity greater than 10'4 ohm ~ cm, resin capable of having a high quantity of trapped charge. Preferred resins include polypropylene, poly(4-methyl-1-pentene) and blends thereof. The resin should be substantially free from materials such as antistatic agents which could increase the electrical conductivity or otherwise interfere with the ability of the 3 o fibers to accept and hold electrostatic charges. The melt blown microfibers can be of a single resin, formed of a resin blend, e.g., polypropylene and poly(4-WO 95/05501 PCTlUS94/0927 ~~ ~126y methyl-1-pentene), or formed of two resins in layered or core/sheath configurations. When polypropylene and poly(4-methyl-1-pentene) are used in layered or core/sheath configurations, the poly(4-methyl-1-pentene) is preferably on the outer surface. ' Blown microfibers for fibrous electret filters of the invention typically have an effective fiber diameter of from about 3 to 30 micrometers preferably from about 7 to 15 micrometers, as calculated according to the method set forth in Davies, C.N., "The Separation of Airborne Dust and Particles," Institution of Mechanical Engineers, London, Proceedings 1B, 1952.
to Staple fibers may also be present in the web. The presence of staple fibers generally provides a more lofty, less dense web than a web of only blown microfibers. Preferably, no more than about 90 weight percent staple fibers are present, more preferably no more than about 70 weight percent.
Such webs containing staple fiber are disclosed in U.S. Pat. No. 4,118,531 (Hauser).
Sorbent particulate material such as activated carbon or alumina may also be included in the web. Such particles may be present in amounts up to about 80 volume percent of the contents of the web. Such particle-loaded webs are described, for example, in U.S. Pat. No. 3,971,373 (Braun), U.S. Pat. No.
4,100,324 (Anderson) and U.S. Pat. No. 4,429,001 (Kolpin et al.).
The electret filter media prepared according to the method of the present invention preferably has a basis weight in the range of about 10 to 500 g/mz, more preferably about 10 to 100 g/m2. In making melt-blown microfiber webs, the basis weight can be controlled, for example, by changing either the 2 5 collector speed or the die throughput. The thickness of the filter media is preferably about 0.25 to 20 mm, more preferably about 0.5 to 2 mm. The electret filter media and the polypropylene resin from which it is produced should not be subjected to any unnecessary treatment which might increase its , electrical conductivity, e.g., exposure to gamma rays, ultraviolet irradiation, 3 o pyrolysis, oxidation, etc. .
Nonwoven microfiber webs useful in the present invention may be prepared using an apparatus as shown in FIG. 1. Such an apparatus includes a die 20 which has an extrusion chamber 21 through which liquified fiber-forming material is advanced; die orifices 22 arranged in line across the forward end of the die and through which the fiber-forming material is extruded; and cooperating gas orifices 23 through which a gas, typically heated air, is forced at high velocity. The high velocity gaseous stream draws out and attenuates the extruded fiber-forming material, whereupon the fiber-forming material solidifies as microfibers during travel to a collector 24 to form web 25.
1 o When staple fibers are present in the web, they may be introduced through use of a lickerin roll 32 disposed above the microfiber blowing apparatus as shown in FIG. 1. A web 27 of staple fibers, typically a loose, nonwoven web such as prepared on a garnet or RANDO-WEBBER apparatus, is propelled along table 28 under drive roll 29 where the leading edge engages against the lickerin roll 32. The lickerin roll 32 picks off fibers from the leading edge of web 27 separating the fibers from one another. The picked fibers are conveyed in an air stream through an inclined trough or duct 30 and into the stream of blown microfibers where they become mixed with the blown microfibers.
2 o When particulate matter is to be introduced into the web it may be added using a loading mechanism similar to duct 30.
Hydrocharging of the web is carried out by impinging jets of water or a stream of water droplets onto the web at a pressure sufficient to provide the web with filtration enhancing electret charge. The pressure necessary to achieve optimum results will vary depending on the type of sprayer used, the type of polymer from which the web is formed, the thickness and density of the web and whether pretreatment such as corona charging was carried out prior to hydrocharging. Generally, pressures in the range of about 10 to 500 psi (69 to 3450 kPa) are suitable. Preferably the water used to provide the water droplets 3 o is relatively pure. Distilled or deionized water is preferable to tap water.
The electret filter media prepared according to the method of the present invention preferably has a basis weight in the range of about 10 to 500 g/mz, more preferably about 10 to 100 g/m2. In making melt-blown microfiber webs, the basis weight can be controlled, for example, by changing either the 2 5 collector speed or the die throughput. The thickness of the filter media is preferably about 0.25 to 20 mm, more preferably about 0.5 to 2 mm. The electret filter media and the polypropylene resin from which it is produced should not be subjected to any unnecessary treatment which might increase its , electrical conductivity, e.g., exposure to gamma rays, ultraviolet irradiation, 3 o pyrolysis, oxidation, etc. .
Nonwoven microfiber webs useful in the present invention may be prepared using an apparatus as shown in FIG. 1. Such an apparatus includes a die 20 which has an extrusion chamber 21 through which liquified fiber-forming material is advanced; die orifices 22 arranged in line across the forward end of the die and through which the fiber-forming material is extruded; and cooperating gas orifices 23 through which a gas, typically heated air, is forced at high velocity. The high velocity gaseous stream draws out and attenuates the extruded fiber-forming material, whereupon the fiber-forming material solidifies as microfibers during travel to a collector 24 to form web 25.
1 o When staple fibers are present in the web, they may be introduced through use of a lickerin roll 32 disposed above the microfiber blowing apparatus as shown in FIG. 1. A web 27 of staple fibers, typically a loose, nonwoven web such as prepared on a garnet or RANDO-WEBBER apparatus, is propelled along table 28 under drive roll 29 where the leading edge engages against the lickerin roll 32. The lickerin roll 32 picks off fibers from the leading edge of web 27 separating the fibers from one another. The picked fibers are conveyed in an air stream through an inclined trough or duct 30 and into the stream of blown microfibers where they become mixed with the blown microfibers.
2 o When particulate matter is to be introduced into the web it may be added using a loading mechanism similar to duct 30.
Hydrocharging of the web is carried out by impinging jets of water or a stream of water droplets onto the web at a pressure sufficient to provide the web with filtration enhancing electret charge. The pressure necessary to achieve optimum results will vary depending on the type of sprayer used, the type of polymer from which the web is formed, the thickness and density of the web and whether pretreatment such as corona charging was carried out prior to hydrocharging. Generally, pressures in the range of about 10 to 500 psi (69 to 3450 kPa) are suitable. Preferably the water used to provide the water droplets 3 o is relatively pure. Distilled or deionized water is preferable to tap water.
WO 95/05501 PCT/U594/09275~
The jets of water or stream of water droplets can be provided by any suitable spray means. Those apparatus useful for hydraulically entangling fibers are generally useful in the method of the present invention, although operation is carned out at lower pressures in hydrocharging than generally used ' in hydroentangling.
An example of a suitable spray means is shown in FIG. 2 where fibrous web 10 is transported on support means 11. The transport means may be in the form of a belt, preferably porous, such as a mesh screen or fabric. Water jets 12 in water jet head 13 provide the water spray with a pump (not shown) 1o providing the water pressure. Water jets 12 impinge on web 10 at impingement points 12'. Preferably, a vacuum is provided beneath a porous support to aid in passage of the spray through the web and to reduce drying energy requirements.
Further examples of spray means suitable for use in the method of the present invention include nebulizers such as that shown in FIG. 3 wherein water provided through water line 14 and pressurized air provided through air line are supplied to a nozzle 16 to provide a spray mist to impact web 10 and pump action sprayers such as that shown in FIG. 4 where a pump handle 17 forces water provided by water supply means 18 through nozzle 19 to provide a spray 2 0 mist.
In the following examples, all percentages and parts are by weight unless otherwise noted. The following test method was used to evaluate the examples.
2 5 DOP Penetration and Pressure Drop Dioctyl phthalate (DOP) 0.3 micrometer diameter particles at a concentration of between 70 and 110 mg/m3 are generated using a TSI No. 212 sprayer with four orifices and 30 psi (207 kPa) clean air. The particles are forced through a sample of filter media which is 11.45 cm in diameter at a rate 3 0 of 42.5 L/min, which is a face velocity of 6.9 centimeters per second. The .
sample was exposed to the aerosol for 30 seconds. The penetration is measured with an optical scattering chamber, Percent Penetration Meter Model TPA-8F
available from Air Techniques Inc. The DOP penetration is preferably less than about 70%, more preferably less than about 40%. The pressure drop is measured at a flow rate of 42.5 Llmin and a face velocity of 6.9 cm/sec using an electronic manometer. Pressure drop is reported as DP in mm of water.
Preferably the,pressure drop is less than about 4 mm of water, more preferably less than about 3 mm of water for a single layer of web.
The penetration and pressure drop are used to calculate a quality factor "QF value" from the natural log (ln) of the DOP penetration by the following 1 o formula:
DOP Penetration (%)~
QF[ 1/mm H20] _ -Ln 100 Pressure Drop [mm H20]
A higher initial QF value indicates better initial filtration performance.
Decreased QF values effectively correlate with decreased filtration performance. Generally a QF value of at least about 0.25 is preferred, a value of at least about 0.5 is more preferred and a value of at least about 1 is most 2 o preferred.
Ciearette Smoke Adsorption Test The cigarette smoke adsorption test was performed in a test chamber having rectangular dimensions with a volume of 1 m3 which contained an 2 5 aspirator (CAM 770 Room Air Cleaner, Norelco Company) fitted with a flat filter sample (14 cm x 14 cm). A smoker device capable of smoking a predetermined number of cigarettes (1-10) emitted smoke within the test chamber during a controlled burn time of 4 to 5 minutes. A fan provided uniform mixing of the cigarette smoke generated within the test chamber. A
3 0 laser particle counter (Model PMS LAS-X from Particle Measurement System, Colorado) having a sampling flow rate of 5 cc/sec and a detection range of 0.1 to 7.5 micrometer particle size monitored the particle concentration per count within the test chamber environment. The particle trapping efficiency and the WO 95/05501 PCT/US94/09275~
pressure drop of the filter samples were measured before and after the adsorption of the cigarette smoke.
The particle trapping efficiency of the filter media was measured using a TSI AFT-8110 automated filter tester (TSI, St. Paul, MN) with NaCI particles ' and a face velocity of air passing through the sample of 26.7 cm/sec. The concentration of the NaCI particles, C,~ and Coi,.i., at positions upstream and downstream, respectively, of the filter samples were measured using the photometer in the TSI AFT-8110 and the particle trapping efficiency, E, of the filter was calculated using the formula:
l0 E=(1-[Cot,.,./Cr"])x 100%.
Ambient Air Particle Loading Test Filter samples were subjected to ambient air at a flow rate of 149 ft3/min (250 m3/hr) for extended periods of time using samples 3~ mm x 116 mm and then challenged with particles of 0.3 micrometers and 1.0 micrometers in size.
The resultant particle trapping efficiencies were measured as described in the cigarette smoke adsorption test both prior to the challenge and after designated ambient air loading times.
_g_ WO 95/05501 r ; , , PCTlUS94/09275 . i Examples 1-7 and Comparative Examples C1-C2 A polypropylene (ESCORENE 35056, available from Exxon Corp.) microfiber web was prepared as described in Wente, Van A., "Superfine Thermoplastic Fibers," Industrial En ineering Chemistry, vol. 48, pp. 1342-1346. The web had a basis weight of 55 g/m2 and a thickness of 0.1 cm. The effective fiber diameter of the fibers was 7.6 ~cm. Samples of the web were subjected to impingement of water jets provided by a hydroentangler (L,aboratory Model, serial no. 101, available from Honeycomb Systems Corp.), similar to that shown in FIG. 1, which had a spray bar width of 24 in (0.6 m) 1 o with 40 spray orifices, each 0.005 in (0.13 mm) in diameter, per inch (2.5 cm) width at various water pressures as set forth in Table 1. Each sample passed beneath the spray bar at a rate of 3.5 m/min, and was treated once on each face, vacuum extracted and dried at 70°C for one hour. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 1.
Pressure Pen x m 1 lkPa) 2 o C 1 34.5 78 0.09 C2 69 72 0.11 1 172 39 0.31 2 345 32 0.37 3 690 35 0.34 2 5 4 1380 39 0.34 5 2070 43 0.34 6 2760 46 0.31 7 3450 46 0.34 3 o As can be seen from the data in Table 1, hydrocharging (at pressures of at least about 170 kPa) develops useful levels of electret enhanced filtration characteristics in this web.
WO 95/05501 PCT/US94/09275~
v Examples 8-15 and Comparative Examples C3-C4 A web was prepared as in Examples 1-7 and subjected to corona treatment by passing the web, in contact with an aluminum ground plane, under a positive DC corona twice at a rate of 1.2 m/min with the current maintained ' at about 0.01 mA/cm corona source and the corona source was about 4 cm from the ground plate. Samples of this web were then subjected to impingement of water jets as in Examples 1-7 at various pressures as set forth in Table 2. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality 1 o factor (QF) are reported in Table 2.
Table 2 Pressure Pen x m 1 lkPal C3 0 27 0.38 C4 69 21 0.46 8 172 16 0.55 9 345 15 0.57 2 0 10 690 15 0.61 11 1380 15 0.66 12 2070 13 0.80 13 2760 14 0.79 14 3450 18 0.75 2 5 15 4140 25 0.
As can be seen from the data in Table 2, hydrocharging (at pressures greater than about 170 kPa) increased the electret filtration characteristics of this web.
The jets of water or stream of water droplets can be provided by any suitable spray means. Those apparatus useful for hydraulically entangling fibers are generally useful in the method of the present invention, although operation is carned out at lower pressures in hydrocharging than generally used ' in hydroentangling.
An example of a suitable spray means is shown in FIG. 2 where fibrous web 10 is transported on support means 11. The transport means may be in the form of a belt, preferably porous, such as a mesh screen or fabric. Water jets 12 in water jet head 13 provide the water spray with a pump (not shown) 1o providing the water pressure. Water jets 12 impinge on web 10 at impingement points 12'. Preferably, a vacuum is provided beneath a porous support to aid in passage of the spray through the web and to reduce drying energy requirements.
Further examples of spray means suitable for use in the method of the present invention include nebulizers such as that shown in FIG. 3 wherein water provided through water line 14 and pressurized air provided through air line are supplied to a nozzle 16 to provide a spray mist to impact web 10 and pump action sprayers such as that shown in FIG. 4 where a pump handle 17 forces water provided by water supply means 18 through nozzle 19 to provide a spray 2 0 mist.
In the following examples, all percentages and parts are by weight unless otherwise noted. The following test method was used to evaluate the examples.
2 5 DOP Penetration and Pressure Drop Dioctyl phthalate (DOP) 0.3 micrometer diameter particles at a concentration of between 70 and 110 mg/m3 are generated using a TSI No. 212 sprayer with four orifices and 30 psi (207 kPa) clean air. The particles are forced through a sample of filter media which is 11.45 cm in diameter at a rate 3 0 of 42.5 L/min, which is a face velocity of 6.9 centimeters per second. The .
sample was exposed to the aerosol for 30 seconds. The penetration is measured with an optical scattering chamber, Percent Penetration Meter Model TPA-8F
available from Air Techniques Inc. The DOP penetration is preferably less than about 70%, more preferably less than about 40%. The pressure drop is measured at a flow rate of 42.5 Llmin and a face velocity of 6.9 cm/sec using an electronic manometer. Pressure drop is reported as DP in mm of water.
Preferably the,pressure drop is less than about 4 mm of water, more preferably less than about 3 mm of water for a single layer of web.
The penetration and pressure drop are used to calculate a quality factor "QF value" from the natural log (ln) of the DOP penetration by the following 1 o formula:
DOP Penetration (%)~
QF[ 1/mm H20] _ -Ln 100 Pressure Drop [mm H20]
A higher initial QF value indicates better initial filtration performance.
Decreased QF values effectively correlate with decreased filtration performance. Generally a QF value of at least about 0.25 is preferred, a value of at least about 0.5 is more preferred and a value of at least about 1 is most 2 o preferred.
Ciearette Smoke Adsorption Test The cigarette smoke adsorption test was performed in a test chamber having rectangular dimensions with a volume of 1 m3 which contained an 2 5 aspirator (CAM 770 Room Air Cleaner, Norelco Company) fitted with a flat filter sample (14 cm x 14 cm). A smoker device capable of smoking a predetermined number of cigarettes (1-10) emitted smoke within the test chamber during a controlled burn time of 4 to 5 minutes. A fan provided uniform mixing of the cigarette smoke generated within the test chamber. A
3 0 laser particle counter (Model PMS LAS-X from Particle Measurement System, Colorado) having a sampling flow rate of 5 cc/sec and a detection range of 0.1 to 7.5 micrometer particle size monitored the particle concentration per count within the test chamber environment. The particle trapping efficiency and the WO 95/05501 PCT/US94/09275~
pressure drop of the filter samples were measured before and after the adsorption of the cigarette smoke.
The particle trapping efficiency of the filter media was measured using a TSI AFT-8110 automated filter tester (TSI, St. Paul, MN) with NaCI particles ' and a face velocity of air passing through the sample of 26.7 cm/sec. The concentration of the NaCI particles, C,~ and Coi,.i., at positions upstream and downstream, respectively, of the filter samples were measured using the photometer in the TSI AFT-8110 and the particle trapping efficiency, E, of the filter was calculated using the formula:
l0 E=(1-[Cot,.,./Cr"])x 100%.
Ambient Air Particle Loading Test Filter samples were subjected to ambient air at a flow rate of 149 ft3/min (250 m3/hr) for extended periods of time using samples 3~ mm x 116 mm and then challenged with particles of 0.3 micrometers and 1.0 micrometers in size.
The resultant particle trapping efficiencies were measured as described in the cigarette smoke adsorption test both prior to the challenge and after designated ambient air loading times.
_g_ WO 95/05501 r ; , , PCTlUS94/09275 . i Examples 1-7 and Comparative Examples C1-C2 A polypropylene (ESCORENE 35056, available from Exxon Corp.) microfiber web was prepared as described in Wente, Van A., "Superfine Thermoplastic Fibers," Industrial En ineering Chemistry, vol. 48, pp. 1342-1346. The web had a basis weight of 55 g/m2 and a thickness of 0.1 cm. The effective fiber diameter of the fibers was 7.6 ~cm. Samples of the web were subjected to impingement of water jets provided by a hydroentangler (L,aboratory Model, serial no. 101, available from Honeycomb Systems Corp.), similar to that shown in FIG. 1, which had a spray bar width of 24 in (0.6 m) 1 o with 40 spray orifices, each 0.005 in (0.13 mm) in diameter, per inch (2.5 cm) width at various water pressures as set forth in Table 1. Each sample passed beneath the spray bar at a rate of 3.5 m/min, and was treated once on each face, vacuum extracted and dried at 70°C for one hour. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 1.
Pressure Pen x m 1 lkPa) 2 o C 1 34.5 78 0.09 C2 69 72 0.11 1 172 39 0.31 2 345 32 0.37 3 690 35 0.34 2 5 4 1380 39 0.34 5 2070 43 0.34 6 2760 46 0.31 7 3450 46 0.34 3 o As can be seen from the data in Table 1, hydrocharging (at pressures of at least about 170 kPa) develops useful levels of electret enhanced filtration characteristics in this web.
WO 95/05501 PCT/US94/09275~
v Examples 8-15 and Comparative Examples C3-C4 A web was prepared as in Examples 1-7 and subjected to corona treatment by passing the web, in contact with an aluminum ground plane, under a positive DC corona twice at a rate of 1.2 m/min with the current maintained ' at about 0.01 mA/cm corona source and the corona source was about 4 cm from the ground plate. Samples of this web were then subjected to impingement of water jets as in Examples 1-7 at various pressures as set forth in Table 2. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality 1 o factor (QF) are reported in Table 2.
Table 2 Pressure Pen x m 1 lkPal C3 0 27 0.38 C4 69 21 0.46 8 172 16 0.55 9 345 15 0.57 2 0 10 690 15 0.61 11 1380 15 0.66 12 2070 13 0.80 13 2760 14 0.79 14 3450 18 0.75 2 5 15 4140 25 0.
As can be seen from the data in Table 2, hydrocharging (at pressures greater than about 170 kPa) increased the electret filtration characteristics of this web.
Examples 16-21 and Comparative Exam lp a CS
A web was prepared as in Examples 1-7 except the polymer used was poly-4-methyl-1-pentene (TPX MX-007, available from Mitsui Chemical Co.
The web was subjected to corona treatment as in Examples 8-15. In Examples 16-21, samples of this web were then subjected to impingement of water droplets as in Examples 1-7 at various pressures as set forth in Table 3. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 3.
a 1 3 Pressure Pen x m 1 ~kPal ~ ~F
CS 0 19 0.85 16 69 11 1.31 17 172 2.1 2.06 18 345 2.0 2.06 19 1035 2.9 1.97 2 0 20 1380 3.1 1.75 21 2760 11 1.12 As can be seen from the data in Table 3, hydrocharging poly-4-methyl-1-pentene webs at pressures of about 69 kPa and greater produced webs having 2 5 excellent electret enhanced filtration characteristics.
Examples 22-24 and Comparative Examples C6-C8 In Examples 22-24 and Comparative Examples C6-C8, polypropylene (ESCORENE 3505G) microfiber webs containing 50 weight percent staple fiber 3 o were prepared as described in U.S. Pat. No. 4,118,531 (Hauser). Each web weighed about SO g/m2. In Example 22 and Comparative Example C6, the staple fiber was 17 denier, 5.1 cm long polypropylene, natural, available from ~~ 81~ ~. 6 i Synthetic Industries (17d PP); in Example 23 and Comparative Example C7, the staple fiber was 15 denier, 3.1 cm polyester, KODEL K-431 available from Eastman Chemical Company (lSd PET); and in Example 24 and Comparative Example C8, the staple fiber was 6 denier, 5.1 cm polyester, KODEL K-211 available from Eastman Chemical Company (6d PET). Prior to use, the polyester staple fibers were washed to remove surface finish using about 2 weight percent LIQUINOX (available from Alconox, Inc.) in hot water (about 140°F, 60°C) with agitation for about 5 minutes, rinsed and dried.
Samples of each web were subjected to corona treatment as described in Examples 8-15. In Examples 22-24, the webs were subsequently subjected to impingement of water spray as in Examples 1-7 at a rate of 3.5 m/min with a hydrostatic pressure of 690 kPa. The treated samples were tested for DOP
penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 4.
Table 4 Pen x m le Fiber Type ~ ~QF
22 17d PP 49 1.67 2 0 23 15d PET 44 2.24 24 6d PET 47 1.82 C6 17d PP 68 0.95 C7 15d PET 72 0.97 C8 6d PET 76 0.82 As can be seen from the data in Table 4, hydrocharging webs of mixtures of melt blown microfibers and staple fibers after corona treatment increases the Quality Factor when compared to webs treated only with corona charging. The most significant increase was seen in the web containing 50 , 3 o percent 15 denier polyester staple fiber.
A web was prepared as in Examples 1-7 except the polymer used was poly-4-methyl-1-pentene (TPX MX-007, available from Mitsui Chemical Co.
The web was subjected to corona treatment as in Examples 8-15. In Examples 16-21, samples of this web were then subjected to impingement of water droplets as in Examples 1-7 at various pressures as set forth in Table 3. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 3.
a 1 3 Pressure Pen x m 1 ~kPal ~ ~F
CS 0 19 0.85 16 69 11 1.31 17 172 2.1 2.06 18 345 2.0 2.06 19 1035 2.9 1.97 2 0 20 1380 3.1 1.75 21 2760 11 1.12 As can be seen from the data in Table 3, hydrocharging poly-4-methyl-1-pentene webs at pressures of about 69 kPa and greater produced webs having 2 5 excellent electret enhanced filtration characteristics.
Examples 22-24 and Comparative Examples C6-C8 In Examples 22-24 and Comparative Examples C6-C8, polypropylene (ESCORENE 3505G) microfiber webs containing 50 weight percent staple fiber 3 o were prepared as described in U.S. Pat. No. 4,118,531 (Hauser). Each web weighed about SO g/m2. In Example 22 and Comparative Example C6, the staple fiber was 17 denier, 5.1 cm long polypropylene, natural, available from ~~ 81~ ~. 6 i Synthetic Industries (17d PP); in Example 23 and Comparative Example C7, the staple fiber was 15 denier, 3.1 cm polyester, KODEL K-431 available from Eastman Chemical Company (lSd PET); and in Example 24 and Comparative Example C8, the staple fiber was 6 denier, 5.1 cm polyester, KODEL K-211 available from Eastman Chemical Company (6d PET). Prior to use, the polyester staple fibers were washed to remove surface finish using about 2 weight percent LIQUINOX (available from Alconox, Inc.) in hot water (about 140°F, 60°C) with agitation for about 5 minutes, rinsed and dried.
Samples of each web were subjected to corona treatment as described in Examples 8-15. In Examples 22-24, the webs were subsequently subjected to impingement of water spray as in Examples 1-7 at a rate of 3.5 m/min with a hydrostatic pressure of 690 kPa. The treated samples were tested for DOP
penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 4.
Table 4 Pen x m le Fiber Type ~ ~QF
22 17d PP 49 1.67 2 0 23 15d PET 44 2.24 24 6d PET 47 1.82 C6 17d PP 68 0.95 C7 15d PET 72 0.97 C8 6d PET 76 0.82 As can be seen from the data in Table 4, hydrocharging webs of mixtures of melt blown microfibers and staple fibers after corona treatment increases the Quality Factor when compared to webs treated only with corona charging. The most significant increase was seen in the web containing 50 , 3 o percent 15 denier polyester staple fiber.
Examples 25-26 and Comparative Example C9 A polypropylene web was prepared as in Examples 1-7. The web had a basis weight of 54 g/m2 and a thickness of 1.04 mm. The effective fiber " diameter was 7.5 ~cm. In Comparative Example C9, a sample of the web was corona charged as in Examples 8-15. In Example 25, a sample was hydrocharged using a nebulizer (Model SCD 052H, available from Sonic Development Corp., resonator cap removed) with an air pressure of 380 to 414 kPa and water at atmospheric pressure at a distance of about 7 to 12 cm on each side. In Example 26, a sample was corona charged as in Comparative 1 o Example C9 and then hydrocharged as in Example 25. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 5.
Table 5 Pen x m le C9 25 0.56 45.5 0.36 20 26 21 0.67 As can be seen from the data in Table 5, hydrocharging this web with the nebulizer (Example 25) provided enhanced filtration characteristics although the Quality Factor was not as high as that charged only with corona charging 25 (Comparative Example C9). Hydrocharging with the nebulizer after corona treatment provided the highest Quality Factor in the examples in Table 5.
~cample 27 and Comparative Example C10 A web was prepared as in Examples 1-7 except the polymer used was a 3 o pellet blend of 75 % polypropylene (FINA 3860X, available from Fina Oil &
Chemical Co.) and 25 % poly(4-methyl-1-pentene) (TPX MX-007, available from Mitsui Chemical Co.). The web was 1.0 mm thick and had a basis WO 95/05501 PC'1'/US94/09275-weight of 55 g/mz. The effective fiber diameter was 8.1 ~,m. In Example 27, a sample of the web was subjected to corona treatment and then to impingement of jets of water as in Examples 8-15 using water pressure of 345 kPa (50 psi).
In Comparative Example C10, a sample was subjected to only corona treatment. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 6.
Ta I
Pen 27 6.8 1.16 C10 29 0.51 As can be seen from the data in Table 6, hydrocharging significantly enhanced the filtration characteristics of the web of Example 27 over that of the web of Comparative Example C 10 which was only corona charged.
2 o xample 28 A polypropylene/poly(4-methyl-1-pentene) multilayer microfiber was prepared as in Examples 1-7 except the apparatus utilized two extruders and a three-layer feedblock (splitter assembly) following the method for forming microfiber webs having layered fibers as described in U.S. Pat. No. 5,207,970 25 (Joseph et al.). The first extruder delivered a melt stream of a 50 melt flow rate polypropylene resin, available from FINA Oil and Chemical Co., to the feedblock assembly which heated the resin to about 320°C. The second extruder, which heated the resin to about 343°C, delivered a melt stream of poly(4-methyl-1-pentene) supplied as TPX' grade MX-007 by Mitsui 3 o Petrochemical Industries, Ltd. to the feedblock. The feedblock split the two polymer streams. The polymer melt streams were merged in an alternating fashion into a three-layer melt stream on exiting the feedblock, with the outer layers being the poly(4-methyl-1-pentene) resin. The gear pumps were adjusted WO 95/05501 ' PCT/US94/09275 so that a 75:25 pump ratio of polypropylene:poly(4-methyl-1-pentene) polymer melt was delivered to the feedblock assembly. Webs were collected at a collector to die distance of 28 cm (11 in.). The resulting web of three-layer microfibers had an effective fiber diameter of less than about 8 micrometers and a basis weight of 55 glm2. The web was subjected to corona treatment as described in Examples 8-15, then, to impingement of water as described in Examples 1-7 using a water pressure of 345 kPa. The web was then subjected to vacuum extraction and dried at 70°C for one hour. The pressure drop and penetration were measured on the web before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 29 A web having a basis weight of 55 g/m2 and comprising three-layer microfibers having an effective fiber diameter less than about 8 micrometers was prepared as in Example 28, except the polypropylene and the poly(4-methyl-1-pentene) melt streams were delivered to the three-layer feedblock at a 50:50 ratio and the collector to die distance was 23 cm (9 inches). The 2 o resulting web was corona treated and subsequently subjected to impingement of water jets and dried as in Example 28. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 30 A web having a basis weight of 55 g/mZ and comprising three-layer microfibers having an effective fiber diameter less than about 8 micrometers 3 o was prepared as in Example 28, except the polypropylene and poly(4-methyl-pentene) melt streams were delivered to the three-layer feedblock in a 25:75 WO 95/05501 , PCT/US94/09275~
ratio and the collector to die distance was 7.5 inches (19 cm). The resulting web was corona treated and subsequently subjected to impingement of water jets and dried as in Example 28. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 31 l0 A web of the poly(4-methyl-1-pentene) was prepared as in Example 28, except only one extruder, which heated the resin to 343°C, was used.
The extruder was connected directly to the die through a gear pump. The collector distance from the die was 19 cm (7.5 inches). The resulting web having an effective fiber diameter of 8.5 micrometers and a basis weight of 55 g/m2 was corona treated and subsequently subjected to impingement of water jets and dried as in Example 28. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 32 A web having a basis weight of 55 glmz and comprising three-layer microfibers having an effective fiber diameter less than about 8 micrometers was prepared as in Example 28, except the second extruder delivered a melt 2 5 stream of a pellet blend of 50 melt flow polypropylene resin, available from FINA, and poly(4-methyl-1-pentene) resin (Mitsui "TPX" grade MX-007) to the feedblock. The polymer melt streams were merged in an alternating fashion into a three layer melt stream, with the outer layers being pellet blend (75 weight percent polypropylene:25 weight percent poly(4-methyl-1-pentene). The 3 o gear pumps were adjusted to deliver a 50:50 weight ratio of polypropylene:pellet blend polymer melt to the feed block assembly. The WO 95/05501 216 8 ~ ~ 6 PCT/US94/09275 collector distance from the die was 19 cm (7.5 in). The resulting web was corona treated and subsequently subjected to impingement of water jets and dried as per Example 28 treatment. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Table 7 1 o Pen % QF
Corona + Corona +
Pen % QF Water Jet Water Jet xam le Corona Only Corona Only Im ingement Impin eg ment 28 19.7 0.75 3.7 1.45 29 15.4 0.8 6.3 1.30 30 15.6 0.9 4.8 1.49 31 19.4 0.73 2.5 1.52 32 39.0 0.42 9.1 1.2 2 o As can be seen from the data in Table 7, the webs containing fibers having outer layers of, or containing poly(4-methyl-1-pentene), showed excellent levels of enhanced filtration characteristics when subjected to both corona treatment and impingement of water jets.
2 5 Example 33 A web having a basis weight of 63 g/m2 and comprising five-layer microfibers having an effective fiber diameter of less than about 10 micrometers was prepared as in Example 28 except that the polypropylene and poly(4-methyl-1-pentene) melt streams were delivered to the five-layer feedblock in a 3 0 50:50 weight ratio. The polymer melt streams were merged in an alternating fashion into a five-layer melt stream on exiting the feedblock, with the outer -1~-WO 95!05501 PCT/US94/09275~
layers being the poly(4-methyl-1-pentene) resin. The resultant web was subjected to corona treatment by passing the web, in contact with an aluminum ground plate, under six positive DC corona sources, sequentially at a rate of m/min with the current maintained at about 0.05 mA/cm and the corona source was about 7 cm from the ground plate. The corona treated web was then subjected to impingement of water jets as in Example 28 except the water pressure was 690 kPa. The web was vacuum extracted and dried in a through-air drier at 82°C for about 45 seconds. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment 1o only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
example 34 A web having a basis weight of 62 g/m2 and comprising five-layer microfibers having an effective fiber diameter less than about 10 micrometers was prepared as in Example 28, except only one extruder, which heated the resin to 340°C was used. The extruder delivered a melt stream of a pellet blend containing 50 weight percent 50 melt flow polypropylene resin and 50 2 o weight percent poly(4-methyl-1-pentene) (Mitsui "TPX" grade MX-007) to the feedblock. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
~,xample 35 A web having a basis weight of 62 g/m2 and comprising five-layer 3 o microfibers having an effective fiber diameter of less than about 10 micrometers was prepared as in Example 33 except the second extruder delivered a melt stream of a poly(4-methyl-1-pentene) supplied as "TPX" grade DX820 by Mitsui Petrochemical Industries, Ltd., to the feedblock. The polymer melt streams were merged in an alternating fashion into a five layer melt stream, with the outer layers being poly(4-methyl-1-pentene). The gear pumps were adjusted to deliver a 50:50 weight ratio of the polypropylene:poly(4-methyl-1-pentene) polymer melt to the feed block assembly. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both to corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
Example 36 A web having a basis weight of 59 g/m2 and comprising five-layer microfibers having an effective fiber diameter of less than about 10 micrometers was prepared as in Example 28 except the second extruder delivered a melt stream of a pellet blend of 80 weight percent 50 melt flow polypropylene resin and 20 weight percent poly(4-methyl-1-pentene) (Mitsui "TPX" grade MX-007) to the feedblock. The polymer melt streams were merged in an alternating 2 0 fashion into a five layer melt stream, with the outer layers being the pellet blend. The gear pumps were adjusted to deliver a 50:50 weight ratio of the polypropylene:pellet blend polymer melt to the feed block assembly. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
WO 95/05501 PCT/US94/0927~
Example 37 A web of poly(4-methyl-1-pentene) (Mitsui "TPX" grade MX-007) was prepared utilizing a five layer melt stream as in Example 28, except only one extruder which heated the resin to 343°C, was used. The extruder was ' connected directly to the die through a gear pump. The resulting web was corona treated and subsequently subjected to impingement of water jets and dried as in Example 33. The basis weight was 65 g/m2 and the effective fiber diameter was less than 10 micrometers. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
T I
Pen ~ QF
QF Corona + Corona +
Pen % Corona Water Jet Water Jet x m le Corona OnIX Onl~ Impin eg'ment Impingement 33 26.7 0.66 7.8 1.31 34 28.7 0.49 11.8 0.94 2 0 35 25. 8 0.55 9.3 1.01 36 26.4 0.56 13.7 0.9 37 25.2 0.51 7.1 1.24 Examples 38a-d. 39a-d and 40a-d Circular filter layers 10.16 cm in diameter and 1.3 mm thick were prepared from web materials prepared as described in Example 35 for Examples 38a-d, Example 36 for Examples 39a-d and Example 37 for Examples 40a-d. Circular filter elements were assembled of various numbers of layers, as indicated in Table 9, of charged electret filter media as in U.S. , 3o Pat. No. 4,886,058 (Brostrom et al.) for the front and rear walls of the filter element. Each assembled filter element had a singular, circular polypropylene breather tube having an inner diameter of 1.91 cm. The filter elements were subjected to the DOP penetration and pressure drop test. The results are reported in Table 9.
Examples 41a-a A web of 50 melt flow polypropylene resin was prepared as in Example 33, except that only one extruder, which heated the resin to 320°C was used, and it was connected directly to the die though a gear pump. The resulting web had a basis weight of 55 g/m2 and an effective fiber diameter of less than about l0 8 micrometers. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33.
Filter elements containing various numbers of layers of the electret web were prepared and tested as in Examples 38-40. The results are set forth in Table 9.
Comparative Example C 11 A web of 50 melt flow polypropylene resin was prepared as in Example 41 except the resultant web was only corona treated. A filter element using six layers of electret filter media was assembled and tested as in Examples 38-40.
2 o The results are set forth in Table 9.
WO PCT/US94/09275", 95/05501 ~~~8i 6 i TABLE
Layers Initial of Filter Pressure Loaded Media Initial Drop Loaded Pressure , per _ Penetration(mm _ PenetrationDrop Ex. wall l % ) H~O) l % ) mm H~
38a 5 0.001 18.5 0.001 18.9 b 4 0.001 15.4 0.003 15.9 c 3 0.007 12.4 0.018 12.8 1 d 2 0.161 9. 6 0. 529 9. 8 o 39a 5 0.002 17.6 0.006 18.0 b 4 0.013 13.8 0.032 14.1 c 3 0.114 11.9 0.294 12.4 d 2 0. 840 8. 9 2.1 S 9. 3 40a 5 0.001 23.3 0.001 23.8 b 4 0.001 18.4 0.001 18.9 c 3 0.080 14.5 0.017 14.9 2 d 2 0.167 10. 8 0. 311 11.1 o 41a 6 0.001 21.4 0.001 21.8 b 5 0. (~ 16.7 0.002 17.0 c 4 0.001 15.0 0.021 15.3 2 d 3 0. 007 12.0 0. 237 12. 4 a 2 0.177 9.1 3.37 9.4 C 11 6 0.015 17.7 0.127 17.4 The data demonstrates that water jet impingement upon a corona treated microfiber filter media of either polypropylene fiber, multilayer fiber construction of polypropylene with poly-4-methyl-1-pentene, and fibers of poly-4-methyl-1-pentene permits less penetration of DOP both initially and at final loading compared with polypropylene microfiber 6-layer construction subjected only to corona treatment. Therefore, filter elements utilizing the water impingement treated microfiber media can be made with fewer layers of media and lower pressure drop across the filter element can result while the filter WO 95/05501 . ; ,a ~ PCTILTS94/09275 element still offers comparable or superior performance levels to corona treated electret filter media having a greater number of layers.
~ Example 42 A filter sample was prepared as in Example 31 except the collector to die distance was 40 cm (16 in), the resin was heated to 372°C, the effective fiber diameter was 14 micrometers, the basis weight was 50 g/m2, and the web was dried at 80°C for about 25 min. The pressure drop was measured. The sample was subjected to the cigarette smoke test and filter efficiency was 1 o determined. The results are shown in Table 10.
Example 43 A filter was prepared as in Example 42 except TPX'~ grade MX-002 poly(4-methyl-1-pentene) was used. The pressure drop was measured. The sample was subjected to the cigarette smoke test and filter efficiency was determined. The results are shown in Table 10.
T ba le 10 Pressure ' Filter Filter Filter 2 0 drop UnchargedInitial EfficiencyEfficiencyEfficiency (mm Hz0) Filter Filter After After After at 26.7 EfficiencyEfficiencyCigaretteCigarettesCigarettes cm/sec E"; (~) E; (qb) E~ (~) E. (~l E~ (gb) 42 2.8 16.5 80.5 ----- 48.8 17.9 2 5 43 3.4 18. 6 67.1 60.3 53.9 34.4 The data in Table 10 illustrates the superior filtration performance of the filters made from poly(4-methyl-1-pentene) and treated by the combination of 3 0 corona and water impingement.
~~~~1~6 Examples 44a and 44b A filter sample was prepared as in Example 31 except the collector to die distance was 11 inches (28 cm) and the effective fiber diameter was 14 micrometers. The web had a basis weight of 40 g/m2 and a thickness of 1.2 mm (0.049 in). A pleated filter element was prepared from the filter web and a scrim of Colback' (80 g/mz, available from BASF Corp.) which had been adhesively adhered to the filter web using about 1 g/m2 adhesive. The filter element was 29 cm long, 10 cm wide and had 52 pleats in its 29 cm length with the pleats having a height of 28 mm. The web was tested for initial efficiency 1 o and pressure drop values as well as for the filter efficiency after ambient air particle loading at particle sizes of 0.3 micrometer diameter (Example 44a) and 1 micrometer diameter (Example 44b). The results are shown in Table 11.
Table 11 Hour Initial exposure 290 Hour Pressure133 HourPressure290 Hourexposure Particle Initial Drop exposureDrop exposurePressure 2 0 Size Efficiency(mm Efficiency(mm EfficiencyDrop fix. um l96) H,OI (96) H~ f~) fmmH,O) 44a 0.3 70.5 10.8 53.8 13.8 47 15.5 44b 1.0 86.8 10.8 79.0 13.8 75 15.5 The data in Table 11 demonstrates that the particle trapping efficiency can be sustained for long periods even under conditions of continuous use with a range of particle sizes.
The various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention and this invention should not be restricted to that set forth herein for illustrative purposes.
Table 5 Pen x m le C9 25 0.56 45.5 0.36 20 26 21 0.67 As can be seen from the data in Table 5, hydrocharging this web with the nebulizer (Example 25) provided enhanced filtration characteristics although the Quality Factor was not as high as that charged only with corona charging 25 (Comparative Example C9). Hydrocharging with the nebulizer after corona treatment provided the highest Quality Factor in the examples in Table 5.
~cample 27 and Comparative Example C10 A web was prepared as in Examples 1-7 except the polymer used was a 3 o pellet blend of 75 % polypropylene (FINA 3860X, available from Fina Oil &
Chemical Co.) and 25 % poly(4-methyl-1-pentene) (TPX MX-007, available from Mitsui Chemical Co.). The web was 1.0 mm thick and had a basis WO 95/05501 PC'1'/US94/09275-weight of 55 g/mz. The effective fiber diameter was 8.1 ~,m. In Example 27, a sample of the web was subjected to corona treatment and then to impingement of jets of water as in Examples 8-15 using water pressure of 345 kPa (50 psi).
In Comparative Example C10, a sample was subjected to only corona treatment. The treated samples were tested for DOP penetration and pressure drop and the quality factor was calculated. The penetration (Pen) and quality factor (QF) are reported in Table 6.
Ta I
Pen 27 6.8 1.16 C10 29 0.51 As can be seen from the data in Table 6, hydrocharging significantly enhanced the filtration characteristics of the web of Example 27 over that of the web of Comparative Example C 10 which was only corona charged.
2 o xample 28 A polypropylene/poly(4-methyl-1-pentene) multilayer microfiber was prepared as in Examples 1-7 except the apparatus utilized two extruders and a three-layer feedblock (splitter assembly) following the method for forming microfiber webs having layered fibers as described in U.S. Pat. No. 5,207,970 25 (Joseph et al.). The first extruder delivered a melt stream of a 50 melt flow rate polypropylene resin, available from FINA Oil and Chemical Co., to the feedblock assembly which heated the resin to about 320°C. The second extruder, which heated the resin to about 343°C, delivered a melt stream of poly(4-methyl-1-pentene) supplied as TPX' grade MX-007 by Mitsui 3 o Petrochemical Industries, Ltd. to the feedblock. The feedblock split the two polymer streams. The polymer melt streams were merged in an alternating fashion into a three-layer melt stream on exiting the feedblock, with the outer layers being the poly(4-methyl-1-pentene) resin. The gear pumps were adjusted WO 95/05501 ' PCT/US94/09275 so that a 75:25 pump ratio of polypropylene:poly(4-methyl-1-pentene) polymer melt was delivered to the feedblock assembly. Webs were collected at a collector to die distance of 28 cm (11 in.). The resulting web of three-layer microfibers had an effective fiber diameter of less than about 8 micrometers and a basis weight of 55 glm2. The web was subjected to corona treatment as described in Examples 8-15, then, to impingement of water as described in Examples 1-7 using a water pressure of 345 kPa. The web was then subjected to vacuum extraction and dried at 70°C for one hour. The pressure drop and penetration were measured on the web before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 29 A web having a basis weight of 55 g/m2 and comprising three-layer microfibers having an effective fiber diameter less than about 8 micrometers was prepared as in Example 28, except the polypropylene and the poly(4-methyl-1-pentene) melt streams were delivered to the three-layer feedblock at a 50:50 ratio and the collector to die distance was 23 cm (9 inches). The 2 o resulting web was corona treated and subsequently subjected to impingement of water jets and dried as in Example 28. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 30 A web having a basis weight of 55 g/mZ and comprising three-layer microfibers having an effective fiber diameter less than about 8 micrometers 3 o was prepared as in Example 28, except the polypropylene and poly(4-methyl-pentene) melt streams were delivered to the three-layer feedblock in a 25:75 WO 95/05501 , PCT/US94/09275~
ratio and the collector to die distance was 7.5 inches (19 cm). The resulting web was corona treated and subsequently subjected to impingement of water jets and dried as in Example 28. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 31 l0 A web of the poly(4-methyl-1-pentene) was prepared as in Example 28, except only one extruder, which heated the resin to 343°C, was used.
The extruder was connected directly to the die through a gear pump. The collector distance from the die was 19 cm (7.5 inches). The resulting web having an effective fiber diameter of 8.5 micrometers and a basis weight of 55 g/m2 was corona treated and subsequently subjected to impingement of water jets and dried as in Example 28. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Example 32 A web having a basis weight of 55 glmz and comprising three-layer microfibers having an effective fiber diameter less than about 8 micrometers was prepared as in Example 28, except the second extruder delivered a melt 2 5 stream of a pellet blend of 50 melt flow polypropylene resin, available from FINA, and poly(4-methyl-1-pentene) resin (Mitsui "TPX" grade MX-007) to the feedblock. The polymer melt streams were merged in an alternating fashion into a three layer melt stream, with the outer layers being pellet blend (75 weight percent polypropylene:25 weight percent poly(4-methyl-1-pentene). The 3 o gear pumps were adjusted to deliver a 50:50 weight ratio of polypropylene:pellet blend polymer melt to the feed block assembly. The WO 95/05501 216 8 ~ ~ 6 PCT/US94/09275 collector distance from the die was 19 cm (7.5 in). The resulting web was corona treated and subsequently subjected to impingement of water jets and dried as per Example 28 treatment. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 7.
Table 7 1 o Pen % QF
Corona + Corona +
Pen % QF Water Jet Water Jet xam le Corona Only Corona Only Im ingement Impin eg ment 28 19.7 0.75 3.7 1.45 29 15.4 0.8 6.3 1.30 30 15.6 0.9 4.8 1.49 31 19.4 0.73 2.5 1.52 32 39.0 0.42 9.1 1.2 2 o As can be seen from the data in Table 7, the webs containing fibers having outer layers of, or containing poly(4-methyl-1-pentene), showed excellent levels of enhanced filtration characteristics when subjected to both corona treatment and impingement of water jets.
2 5 Example 33 A web having a basis weight of 63 g/m2 and comprising five-layer microfibers having an effective fiber diameter of less than about 10 micrometers was prepared as in Example 28 except that the polypropylene and poly(4-methyl-1-pentene) melt streams were delivered to the five-layer feedblock in a 3 0 50:50 weight ratio. The polymer melt streams were merged in an alternating fashion into a five-layer melt stream on exiting the feedblock, with the outer -1~-WO 95!05501 PCT/US94/09275~
layers being the poly(4-methyl-1-pentene) resin. The resultant web was subjected to corona treatment by passing the web, in contact with an aluminum ground plate, under six positive DC corona sources, sequentially at a rate of m/min with the current maintained at about 0.05 mA/cm and the corona source was about 7 cm from the ground plate. The corona treated web was then subjected to impingement of water jets as in Example 28 except the water pressure was 690 kPa. The web was vacuum extracted and dried in a through-air drier at 82°C for about 45 seconds. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment 1o only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
example 34 A web having a basis weight of 62 g/m2 and comprising five-layer microfibers having an effective fiber diameter less than about 10 micrometers was prepared as in Example 28, except only one extruder, which heated the resin to 340°C was used. The extruder delivered a melt stream of a pellet blend containing 50 weight percent 50 melt flow polypropylene resin and 50 2 o weight percent poly(4-methyl-1-pentene) (Mitsui "TPX" grade MX-007) to the feedblock. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
~,xample 35 A web having a basis weight of 62 g/m2 and comprising five-layer 3 o microfibers having an effective fiber diameter of less than about 10 micrometers was prepared as in Example 33 except the second extruder delivered a melt stream of a poly(4-methyl-1-pentene) supplied as "TPX" grade DX820 by Mitsui Petrochemical Industries, Ltd., to the feedblock. The polymer melt streams were merged in an alternating fashion into a five layer melt stream, with the outer layers being poly(4-methyl-1-pentene). The gear pumps were adjusted to deliver a 50:50 weight ratio of the polypropylene:poly(4-methyl-1-pentene) polymer melt to the feed block assembly. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both to corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
Example 36 A web having a basis weight of 59 g/m2 and comprising five-layer microfibers having an effective fiber diameter of less than about 10 micrometers was prepared as in Example 28 except the second extruder delivered a melt stream of a pellet blend of 80 weight percent 50 melt flow polypropylene resin and 20 weight percent poly(4-methyl-1-pentene) (Mitsui "TPX" grade MX-007) to the feedblock. The polymer melt streams were merged in an alternating 2 0 fashion into a five layer melt stream, with the outer layers being the pellet blend. The gear pumps were adjusted to deliver a 50:50 weight ratio of the polypropylene:pellet blend polymer melt to the feed block assembly. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
WO 95/05501 PCT/US94/0927~
Example 37 A web of poly(4-methyl-1-pentene) (Mitsui "TPX" grade MX-007) was prepared utilizing a five layer melt stream as in Example 28, except only one extruder which heated the resin to 343°C, was used. The extruder was ' connected directly to the die through a gear pump. The resulting web was corona treated and subsequently subjected to impingement of water jets and dried as in Example 33. The basis weight was 65 g/m2 and the effective fiber diameter was less than 10 micrometers. The pressure drop and penetration were measured on webs before impingement of water jets (corona treatment only) and after both corona treatment and impingement with water jets and the quality factor was calculated. The penetration and quality factor are reported in Table 8.
T I
Pen ~ QF
QF Corona + Corona +
Pen % Corona Water Jet Water Jet x m le Corona OnIX Onl~ Impin eg'ment Impingement 33 26.7 0.66 7.8 1.31 34 28.7 0.49 11.8 0.94 2 0 35 25. 8 0.55 9.3 1.01 36 26.4 0.56 13.7 0.9 37 25.2 0.51 7.1 1.24 Examples 38a-d. 39a-d and 40a-d Circular filter layers 10.16 cm in diameter and 1.3 mm thick were prepared from web materials prepared as described in Example 35 for Examples 38a-d, Example 36 for Examples 39a-d and Example 37 for Examples 40a-d. Circular filter elements were assembled of various numbers of layers, as indicated in Table 9, of charged electret filter media as in U.S. , 3o Pat. No. 4,886,058 (Brostrom et al.) for the front and rear walls of the filter element. Each assembled filter element had a singular, circular polypropylene breather tube having an inner diameter of 1.91 cm. The filter elements were subjected to the DOP penetration and pressure drop test. The results are reported in Table 9.
Examples 41a-a A web of 50 melt flow polypropylene resin was prepared as in Example 33, except that only one extruder, which heated the resin to 320°C was used, and it was connected directly to the die though a gear pump. The resulting web had a basis weight of 55 g/m2 and an effective fiber diameter of less than about l0 8 micrometers. The resulting web was corona treated and also subsequently subjected to impingement of water jets and dried as in Example 33.
Filter elements containing various numbers of layers of the electret web were prepared and tested as in Examples 38-40. The results are set forth in Table 9.
Comparative Example C 11 A web of 50 melt flow polypropylene resin was prepared as in Example 41 except the resultant web was only corona treated. A filter element using six layers of electret filter media was assembled and tested as in Examples 38-40.
2 o The results are set forth in Table 9.
WO PCT/US94/09275", 95/05501 ~~~8i 6 i TABLE
Layers Initial of Filter Pressure Loaded Media Initial Drop Loaded Pressure , per _ Penetration(mm _ PenetrationDrop Ex. wall l % ) H~O) l % ) mm H~
38a 5 0.001 18.5 0.001 18.9 b 4 0.001 15.4 0.003 15.9 c 3 0.007 12.4 0.018 12.8 1 d 2 0.161 9. 6 0. 529 9. 8 o 39a 5 0.002 17.6 0.006 18.0 b 4 0.013 13.8 0.032 14.1 c 3 0.114 11.9 0.294 12.4 d 2 0. 840 8. 9 2.1 S 9. 3 40a 5 0.001 23.3 0.001 23.8 b 4 0.001 18.4 0.001 18.9 c 3 0.080 14.5 0.017 14.9 2 d 2 0.167 10. 8 0. 311 11.1 o 41a 6 0.001 21.4 0.001 21.8 b 5 0. (~ 16.7 0.002 17.0 c 4 0.001 15.0 0.021 15.3 2 d 3 0. 007 12.0 0. 237 12. 4 a 2 0.177 9.1 3.37 9.4 C 11 6 0.015 17.7 0.127 17.4 The data demonstrates that water jet impingement upon a corona treated microfiber filter media of either polypropylene fiber, multilayer fiber construction of polypropylene with poly-4-methyl-1-pentene, and fibers of poly-4-methyl-1-pentene permits less penetration of DOP both initially and at final loading compared with polypropylene microfiber 6-layer construction subjected only to corona treatment. Therefore, filter elements utilizing the water impingement treated microfiber media can be made with fewer layers of media and lower pressure drop across the filter element can result while the filter WO 95/05501 . ; ,a ~ PCTILTS94/09275 element still offers comparable or superior performance levels to corona treated electret filter media having a greater number of layers.
~ Example 42 A filter sample was prepared as in Example 31 except the collector to die distance was 40 cm (16 in), the resin was heated to 372°C, the effective fiber diameter was 14 micrometers, the basis weight was 50 g/m2, and the web was dried at 80°C for about 25 min. The pressure drop was measured. The sample was subjected to the cigarette smoke test and filter efficiency was 1 o determined. The results are shown in Table 10.
Example 43 A filter was prepared as in Example 42 except TPX'~ grade MX-002 poly(4-methyl-1-pentene) was used. The pressure drop was measured. The sample was subjected to the cigarette smoke test and filter efficiency was determined. The results are shown in Table 10.
T ba le 10 Pressure ' Filter Filter Filter 2 0 drop UnchargedInitial EfficiencyEfficiencyEfficiency (mm Hz0) Filter Filter After After After at 26.7 EfficiencyEfficiencyCigaretteCigarettesCigarettes cm/sec E"; (~) E; (qb) E~ (~) E. (~l E~ (gb) 42 2.8 16.5 80.5 ----- 48.8 17.9 2 5 43 3.4 18. 6 67.1 60.3 53.9 34.4 The data in Table 10 illustrates the superior filtration performance of the filters made from poly(4-methyl-1-pentene) and treated by the combination of 3 0 corona and water impingement.
~~~~1~6 Examples 44a and 44b A filter sample was prepared as in Example 31 except the collector to die distance was 11 inches (28 cm) and the effective fiber diameter was 14 micrometers. The web had a basis weight of 40 g/m2 and a thickness of 1.2 mm (0.049 in). A pleated filter element was prepared from the filter web and a scrim of Colback' (80 g/mz, available from BASF Corp.) which had been adhesively adhered to the filter web using about 1 g/m2 adhesive. The filter element was 29 cm long, 10 cm wide and had 52 pleats in its 29 cm length with the pleats having a height of 28 mm. The web was tested for initial efficiency 1 o and pressure drop values as well as for the filter efficiency after ambient air particle loading at particle sizes of 0.3 micrometer diameter (Example 44a) and 1 micrometer diameter (Example 44b). The results are shown in Table 11.
Table 11 Hour Initial exposure 290 Hour Pressure133 HourPressure290 Hourexposure Particle Initial Drop exposureDrop exposurePressure 2 0 Size Efficiency(mm Efficiency(mm EfficiencyDrop fix. um l96) H,OI (96) H~ f~) fmmH,O) 44a 0.3 70.5 10.8 53.8 13.8 47 15.5 44b 1.0 86.8 10.8 79.0 13.8 75 15.5 The data in Table 11 demonstrates that the particle trapping efficiency can be sustained for long periods even under conditions of continuous use with a range of particle sizes.
The various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention and this invention should not be restricted to that set forth herein for illustrative purposes.
Claims (13)
1. A method of charging a nonwoven web comprising thermoplastic microfibers to provide electret filter media comprising the following steps:
a) impinging on a nonwoven web of thermoplastic nonconductive microfibers, which have a resistivity greater than 10 14 ohm-cm and are capable of having a high quantity of trapped charge, jets of water or a stream of water droplets at a pressure sufficient to provide the web with filtration enhancing electret charge and b) drying said web.
a) impinging on a nonwoven web of thermoplastic nonconductive microfibers, which have a resistivity greater than 10 14 ohm-cm and are capable of having a high quantity of trapped charge, jets of water or a stream of water droplets at a pressure sufficient to provide the web with filtration enhancing electret charge and b) drying said web.
2. The method of claim 1 wherein said jets of water are provided by a hydroentangling device.
3. The method of claim 1 wherein said stream of water droplets is provided by a nebulizer.
4. The method of claim 1 wherein said jets of water or stream of water droplets is provided at a pressure in the range of about 69 to 3450 kPa.
5. The method of claim 1 wherein said web is subjected to corona discharge treatment prior to impingement of said jets of water or said stream of water droplets.
6. The method of claim 1 wherein said web further contains staple fiber.
7. The method of claim 6 wherein said staple fiber comprises up to 90 weight percent of said web.
8. The method of claim 1 wherein said web has a basis weight of about 5 to 500 g/m2.
9. ~The method of claim 1 wherein said web has a thickness of about 0.25 to 20 mm.
10. ~The method of claim 1 wherein said microfibers have an effective fiber diameter of about 3 to 30 µm.
11. ~The method of claim 1 wherein said microfibers are selected from the group consisting of polypropylene, poly(4-methyl-1-pentene) and blends of polypropylene and poly(4-methyl-1-pentene).
12. ~The method of claim 1 wherein said microfibers comprise polypropylene and poly(4-methyl-1-pentene).
13. ~The method of claim 12 wherein the polypropylene and poly(4-methyl-1-pentene) are layered in said microfibers.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002474282A CA2474282C (en) | 1993-08-17 | 1994-08-17 | Electret filter media |
Applications Claiming Priority (3)
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US10751793A | 1993-08-17 | 1993-08-17 | |
US08/107,517 | 1993-08-17 | ||
PCT/US1994/009275 WO1995005501A2 (en) | 1993-08-17 | 1994-08-17 | Method of charging electret filter media |
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CA002474282A Division CA2474282C (en) | 1993-08-17 | 1994-08-17 | Electret filter media |
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CA2168126A1 CA2168126A1 (en) | 1995-02-23 |
CA2168126C true CA2168126C (en) | 2005-07-12 |
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CA002168126A Expired - Fee Related CA2168126C (en) | 1993-08-17 | 1994-08-17 | Method of charging electret filter media |
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US (3) | US5496507A (en) |
EP (2) | EP0845554B1 (en) |
JP (2) | JP3476084B2 (en) |
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CN (1) | CN1052042C (en) |
AU (1) | AU680561B2 (en) |
BR (1) | BR9407259A (en) |
CA (1) | CA2168126C (en) |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106245230A (en) * | 2016-08-31 | 2016-12-21 | 侯慕毅 | A kind of heat-insulating and sound-absorbing material and forming method thereof and special shaping device |
Families Citing this family (321)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090235933A1 (en) * | 2008-08-26 | 2009-09-24 | Trutek Corp. | Electrostatically charged mask filter products and method for increased filtration efficiency |
DE69417041T2 (en) * | 1993-08-17 | 1999-07-15 | Minnesota Mining & Mfg | METHOD FOR CHARGING ELECTRIC FILTER MEDIA |
CA2124237C (en) | 1994-02-18 | 2004-11-02 | Bernard Cohen | Improved nonwoven barrier and method of making the same |
CA2136576C (en) | 1994-06-27 | 2005-03-08 | Bernard Cohen | Improved nonwoven barrier and method of making the same |
CN1067910C (en) * | 1994-10-31 | 2001-07-04 | 金伯利-克拉克环球有限公司 | High density nonwowen filter media |
AU4961696A (en) | 1994-12-08 | 1996-06-26 | Kimberly-Clark Worldwide, Inc. | Method of forming a particle size gradient in an absorbent article |
CA2153278A1 (en) | 1994-12-30 | 1996-07-01 | Bernard Cohen | Nonwoven laminate barrier material |
US5647881A (en) * | 1995-04-20 | 1997-07-15 | Minnesota Mining And Manufacturing Company | Shock resistant high efficiency vacuum cleaner filter bag |
US5742303A (en) * | 1995-05-24 | 1998-04-21 | Hewlett-Packard Company | Trap door spittoon for inkjet aerosol mist control |
AU5747396A (en) | 1995-05-25 | 1996-12-11 | Kimberly-Clark Worldwide, Inc. | Filter matrix |
ZA965786B (en) | 1995-07-19 | 1997-01-27 | Kimberly Clark Co | Nonwoven barrier and method of making the same |
US5908598A (en) * | 1995-08-14 | 1999-06-01 | Minnesota Mining And Manufacturing Company | Fibrous webs having enhanced electret properties |
US5709735A (en) * | 1995-10-20 | 1998-01-20 | Kimberly-Clark Worldwide, Inc. | High stiffness nonwoven filter medium |
US5774141A (en) * | 1995-10-26 | 1998-06-30 | Hewlett-Packard Company | Carriage-mounted inkjet aerosol reduction system |
US5834384A (en) | 1995-11-28 | 1998-11-10 | Kimberly-Clark Worldwide, Inc. | Nonwoven webs with one or more surface treatments |
US5817415A (en) * | 1996-09-12 | 1998-10-06 | E. I. Du Pont De Nemours And Company | Meltblown ionomer microfibers and non-woven webs made therefrom for gas filters |
US5706804A (en) * | 1996-10-01 | 1998-01-13 | Minnesota Mining And Manufacturing Company | Liquid resistant face mask having surface energy reducing agent on an intermediate layer therein |
US6056809A (en) * | 1996-10-18 | 2000-05-02 | Rick L. Chapman | High efficiency permanent air filter and method of manufacture |
US6041782A (en) * | 1997-06-24 | 2000-03-28 | 3M Innovative Properties Company | Respiratory mask having comfortable inner cover web |
US6524488B1 (en) | 1998-06-18 | 2003-02-25 | 3M Innovative Properties Company | Method of filtering certain particles from a fluid using a depth loading filtration media |
US6213122B1 (en) * | 1997-10-01 | 2001-04-10 | 3M Innovative Properties Company | Electret fibers and filter webs having a low level of extractable hydrocarbons |
US6238466B1 (en) | 1997-10-01 | 2001-05-29 | 3M Innovative Properties Company | Electret articles and filters with increased oily mist resistance |
US6068799A (en) * | 1997-10-01 | 2000-05-30 | 3M Innovative Properties Company | Method of making electret articles and filters with increased oily mist resistance |
US6062221A (en) | 1997-10-03 | 2000-05-16 | 3M Innovative Properties Company | Drop-down face mask assembly |
US6732733B1 (en) | 1997-10-03 | 2004-05-11 | 3M Innovative Properties Company | Half-mask respirator with head harness assembly |
US6537932B1 (en) | 1997-10-31 | 2003-03-25 | Kimberly-Clark Worldwide, Inc. | Sterilization wrap, applications therefor, and method of sterilizing |
GB9723740D0 (en) * | 1997-11-11 | 1998-01-07 | Minnesota Mining & Mfg | Respiratory masks incorporating valves or other attached components |
US6102039A (en) | 1997-12-01 | 2000-08-15 | 3M Innovative Properties Company | Molded respirator containing sorbent particles |
US6365088B1 (en) | 1998-06-26 | 2002-04-02 | Kimberly-Clark Worldwide, Inc. | Electret treatment of high loft and low density nonwoven webs |
US6432175B1 (en) * | 1998-07-02 | 2002-08-13 | 3M Innovative Properties Company | Fluorinated electret |
US6110260A (en) * | 1998-07-14 | 2000-08-29 | 3M Innovative Properties Company | Filter having a change indicator |
US6036752A (en) * | 1998-07-28 | 2000-03-14 | 3M Innovative Properties Company | Pleated filter |
US6123752A (en) * | 1998-09-03 | 2000-09-26 | 3M Innovative Properties Company | High efficiency synthetic filter medium |
US6139308A (en) | 1998-10-28 | 2000-10-31 | 3M Innovative Properties Company | Uniform meltblown fibrous web and methods and apparatus for manufacturing |
US6110251A (en) * | 1998-11-03 | 2000-08-29 | Johns Manville International, Inc. | Gas filtration media and method of making the same |
US6280824B1 (en) | 1999-01-29 | 2001-08-28 | 3M Innovative Properties Company | Contoured layer channel flow filtration media |
US6630231B2 (en) * | 1999-02-05 | 2003-10-07 | 3M Innovative Properties Company | Composite articles reinforced with highly oriented microfibers |
US6110588A (en) | 1999-02-05 | 2000-08-29 | 3M Innovative Properties Company | Microfibers and method of making |
US6484723B2 (en) * | 1999-02-11 | 2002-11-26 | Eileen Haas | Tracheostomy air filtration system |
US6103181A (en) * | 1999-02-17 | 2000-08-15 | Filtrona International Limited | Method and apparatus for spinning a web of mixed fibers, and products produced therefrom |
US6394090B1 (en) | 1999-02-17 | 2002-05-28 | 3M Innovative Properties Company | Flat-folded personal respiratory protection devices and processes for preparing same |
US6279570B1 (en) | 1999-03-02 | 2001-08-28 | 3M Innovative Properties Company | Filter support, assembly and system |
US6156086A (en) * | 1999-03-22 | 2000-12-05 | 3M Innovative Properties Company | Dual media vacuum filter bag |
US6391807B1 (en) | 1999-09-24 | 2002-05-21 | 3M Innovative Properties Company | Polymer composition containing a fluorochemical oligomer |
US6288157B1 (en) | 1999-05-11 | 2001-09-11 | 3M Innovative Properties Company | Alkylated fluorochemical oligomers and use thereof |
US6525127B1 (en) | 1999-05-11 | 2003-02-25 | 3M Innovative Properties Company | Alkylated fluorochemical oligomers and use thereof in the treatment of fibrous substrates |
US7049379B2 (en) * | 1999-05-11 | 2006-05-23 | 3M Innovative Properties Company | Alkylated fluorochemical oligomers and use thereof in the treatment of fibrous substrates |
EP1068889A1 (en) * | 1999-07-16 | 2001-01-17 | 3M Innovative Properties Company | High efficiency medical breathing system filter based on a filtration medium of a nonwoven web of thermoplastic resin fibers |
US6273938B1 (en) | 1999-08-13 | 2001-08-14 | 3M Innovative Properties Company | Channel flow filter |
US6627563B1 (en) | 1999-08-19 | 2003-09-30 | 3M Innovative Properties Company | Oily-mist resistant filter that has nondecreasing efficiency |
US6174964B1 (en) | 1999-09-24 | 2001-01-16 | 3M Innovative Properties Company | Fluorochemical oligomer and use thereof |
US6454986B1 (en) * | 1999-10-08 | 2002-09-24 | 3M Innovative Properties Company | Method of making a fibrous electret web using a nonaqueous polar liquid |
US6406657B1 (en) * | 1999-10-08 | 2002-06-18 | 3M Innovative Properties Company | Method and apparatus for making a fibrous electret web using a wetting liquid and an aqueous polar liquid |
US6375886B1 (en) * | 1999-10-08 | 2002-04-23 | 3M Innovative Properties Company | Method and apparatus for making a nonwoven fibrous electret web from free-fiber and polar liquid |
US6604524B1 (en) | 1999-10-19 | 2003-08-12 | 3M Innovative Properties Company | Manner of attaching component elements to filtration material such as may be utilized in respiratory masks |
US6454839B1 (en) | 1999-10-19 | 2002-09-24 | 3M Innovative Properties Company | Electrofiltration apparatus |
EP1235626B1 (en) | 1999-11-23 | 2007-04-04 | Pall Corporation | Conductive filter cartridge |
US6391948B1 (en) | 1999-12-14 | 2002-05-21 | 3M Innovative Properties Company | Triazine compounds and use thereof |
US6743464B1 (en) * | 2000-04-13 | 2004-06-01 | 3M Innovative Properties Company | Method of making electrets through vapor condensation |
US6419729B1 (en) | 2000-04-17 | 2002-07-16 | 3M Innovative Properties Company | Filter assemblies with adhesive attachment systems |
US6746517B2 (en) * | 2000-09-05 | 2004-06-08 | Donaldson Company, Inc. | Filter structure with two or more layers of fine fiber having extended useful service life |
US7270693B2 (en) * | 2000-09-05 | 2007-09-18 | Donaldson Company, Inc. | Polymer, polymer microfiber, polymer nanofiber and applications including filter structures |
US6716274B2 (en) | 2000-09-05 | 2004-04-06 | Donaldson Company, Inc. | Air filter assembly for filtering an air stream to remove particulate matter entrained in the stream |
US6743273B2 (en) * | 2000-09-05 | 2004-06-01 | Donaldson Company, Inc. | Polymer, polymer microfiber, polymer nanofiber and applications including filter structures |
US7115150B2 (en) * | 2000-09-05 | 2006-10-03 | Donaldson Company, Inc. | Mist filtration arrangement utilizing fine fiber layer in contact with media having a pleated construction and floor filter method |
US20020092423A1 (en) * | 2000-09-05 | 2002-07-18 | Gillingham Gary R. | Methods for filtering air for a gas turbine system |
US6800117B2 (en) * | 2000-09-05 | 2004-10-05 | Donaldson Company, Inc. | Filtration arrangement utilizing pleated construction and method |
US6673136B2 (en) * | 2000-09-05 | 2004-01-06 | Donaldson Company, Inc. | Air filtration arrangements having fluted media constructions and methods |
US6740142B2 (en) | 2000-09-05 | 2004-05-25 | Donaldson Company, Inc. | Industrial bag house elements |
JP4581213B2 (en) * | 2000-10-11 | 2010-11-17 | 東レ株式会社 | Manufacturing method of electret processed product |
JP4581212B2 (en) * | 2000-10-11 | 2010-11-17 | 東レ株式会社 | Manufacturing method of electret processed product |
JP3780916B2 (en) * | 2000-11-28 | 2006-05-31 | 東レ株式会社 | Manufacturing method of electret processed product |
US6420024B1 (en) | 2000-12-21 | 2002-07-16 | 3M Innovative Properties Company | Charged microfibers, microfibrillated articles and use thereof |
ES2271224T3 (en) * | 2001-01-17 | 2007-04-16 | Polymer Group Inc. | FILTRATION MEDIA FRAMED BY HYDRAULIC ROUTE AND PROCEDURE. |
US7280014B2 (en) * | 2001-03-13 | 2007-10-09 | Rochester Institute Of Technology | Micro-electro-mechanical switch and a method of using and making thereof |
EP1247558A1 (en) | 2001-04-07 | 2002-10-09 | 3M Innovative Properties Company | A combination filter for filtering fluids |
JP4686896B2 (en) * | 2001-05-11 | 2011-05-25 | 東レ株式会社 | Manufacturing method of electret processed product |
US6680114B2 (en) | 2001-05-15 | 2004-01-20 | 3M Innovative Properties Company | Fibrous films and articles from microlayer substrates |
AU2002303933A1 (en) * | 2001-05-31 | 2002-12-09 | Rochester Institute Of Technology | Fluidic valves, agitators, and pumps and methods thereof |
RU2300543C2 (en) * | 2001-05-31 | 2007-06-10 | Дональдсон Компани, Инк. | Fine fiber compositions, methods for preparation thereof, and a method of manufacturing fine-fiber material |
US6773488B2 (en) | 2001-06-11 | 2004-08-10 | Rochester Institute Of Technology | Electrostatic filter and a method thereof |
US6969484B2 (en) | 2001-06-18 | 2005-11-29 | Toray Industries, Inc. | Manufacturing method and device for electret processed product |
JP3932981B2 (en) * | 2001-06-18 | 2007-06-20 | 東レ株式会社 | Method and apparatus for manufacturing electret processed products |
US6589317B2 (en) | 2001-08-10 | 2003-07-08 | 3M Innovative Properties Company | Structured surface filtration media array |
US7211923B2 (en) * | 2001-10-26 | 2007-05-01 | Nth Tech Corporation | Rotational motion based, electrostatic power source and methods thereof |
US7378775B2 (en) * | 2001-10-26 | 2008-05-27 | Nth Tech Corporation | Motion based, electrostatic power source and methods thereof |
US20050077646A1 (en) * | 2002-01-11 | 2005-04-14 | Japan Vilene Co., Ltd. | Process for producing electret and production apparatus |
JP4352302B2 (en) * | 2002-01-29 | 2009-10-28 | 東洋紡績株式会社 | Electret filter medium and method for producing the same |
US6923182B2 (en) | 2002-07-18 | 2005-08-02 | 3M Innovative Properties Company | Crush resistant filtering face mask |
US6827764B2 (en) * | 2002-07-25 | 2004-12-07 | 3M Innovative Properties Company | Molded filter element that contains thermally bonded staple fibers and electrically-charged microfibers |
JP2004057976A (en) * | 2002-07-30 | 2004-02-26 | Toyobo Co Ltd | Electret filter medium having bio-degradability and its manufacturing method |
JP2004060110A (en) * | 2002-07-30 | 2004-02-26 | Toyobo Co Ltd | Method for producing electret filter medium |
JP4078592B2 (en) * | 2002-08-01 | 2008-04-23 | 東洋紡績株式会社 | Method for producing electret filter media |
US6893711B2 (en) * | 2002-08-05 | 2005-05-17 | Kimberly-Clark Worldwide, Inc. | Acoustical insulation material containing fine thermoplastic fibers |
US20050026527A1 (en) * | 2002-08-05 | 2005-02-03 | Schmidt Richard John | Nonwoven containing acoustical insulation laminate |
KR20110055576A (en) * | 2002-09-16 | 2011-05-25 | 트리오신 홀딩 아이엔씨 | Electrostatically charged filter media incorporating an active agent |
US6874499B2 (en) * | 2002-09-23 | 2005-04-05 | 3M Innovative Properties Company | Filter element that has a thermo-formed housing around filter material |
US6928657B2 (en) * | 2002-10-25 | 2005-08-16 | Kimberly-Clark Worldwide, Inc. | Face mask having hook and loop type fastener |
US20040078860A1 (en) * | 2002-10-25 | 2004-04-29 | Bell Daryl Steven | Single piece face mask |
JP2004195357A (en) * | 2002-12-18 | 2004-07-15 | Toyobo Co Ltd | Method for producing electret filter medium |
US7032751B2 (en) * | 2002-12-19 | 2006-04-25 | Kimberly-Clark Worldwide, Inc. | Dispensing assembly for single piece face mask |
US7217582B2 (en) | 2003-08-29 | 2007-05-15 | Rochester Institute Of Technology | Method for non-damaging charge injection and a system thereof |
US7287328B2 (en) * | 2003-08-29 | 2007-10-30 | Rochester Institute Of Technology | Methods for distributed electrode injection |
US20050106982A1 (en) * | 2003-11-17 | 2005-05-19 | 3M Innovative Properties Company | Nonwoven elastic fibrous webs and methods for making them |
WO2005063359A1 (en) * | 2003-12-25 | 2005-07-14 | Toray Industries, Inc. | Filter material for air filter and filter unit |
US20050148266A1 (en) * | 2003-12-30 | 2005-07-07 | Myers David L. | Self-supporting pleated electret filter media |
US7294175B2 (en) * | 2004-01-13 | 2007-11-13 | Huang Jong T | Personal inhalation filter |
US8581308B2 (en) * | 2004-02-19 | 2013-11-12 | Rochester Institute Of Technology | High temperature embedded charge devices and methods thereof |
US6858297B1 (en) | 2004-04-05 | 2005-02-22 | 3M Innovative Properties Company | Aligned fiber web |
US20050217226A1 (en) * | 2004-04-05 | 2005-10-06 | 3M Innovative Properties Company | Pleated aligned web filter |
US7896940B2 (en) * | 2004-07-09 | 2011-03-01 | 3M Innovative Properties Company | Self-supporting pleated filter media |
US7320722B2 (en) * | 2004-10-29 | 2008-01-22 | 3M Innovative Properties Company | Respiratory protection device that has rapid threaded clean air source attachment |
US7419526B2 (en) * | 2005-03-03 | 2008-09-02 | 3M Innovative Properties Company | Conformal filter cartridges and methods |
WO2006096486A2 (en) * | 2005-03-07 | 2006-09-14 | 3M Innovative Properties Company | Vehicle passenger compartment air filter devices |
US20060231100A1 (en) | 2005-04-15 | 2006-10-19 | Walker Garry J | Supplied air respirator that has an adjustable length hose |
US7536962B2 (en) | 2005-04-19 | 2009-05-26 | Kamterter Ii, L.L.C. | Systems for the control and use of fluids and particles |
US7311050B2 (en) | 2005-04-19 | 2007-12-25 | Kamterter Ii, L.L.C. | Systems for the control and use of fluids and particles |
US8308075B2 (en) | 2005-04-19 | 2012-11-13 | Kamterter Products, Llc | Systems for the control and use of fluids and particles |
JP2008538532A (en) * | 2005-04-22 | 2008-10-30 | スリーエム イノベイティブ プロパティズ カンパニー | Vehicle cabin air filter device |
US7244292B2 (en) * | 2005-05-02 | 2007-07-17 | 3M Innovative Properties Company | Electret article having heteroatoms and low fluorosaturation ratio |
US7244291B2 (en) * | 2005-05-02 | 2007-07-17 | 3M Innovative Properties Company | Electret article having high fluorosaturation ratio |
US7553440B2 (en) * | 2005-05-12 | 2009-06-30 | Leonard William K | Method and apparatus for electric treatment of substrates |
US8171933B2 (en) * | 2005-08-25 | 2012-05-08 | 3M Innovative Properties Company | Respirator having preloaded nose clip |
US7393269B2 (en) | 2005-09-16 | 2008-07-01 | 3M Innovative Properties Company | Abrasive filter assembly and methods of making same |
US20070074731A1 (en) * | 2005-10-05 | 2007-04-05 | Nth Tech Corporation | Bio-implantable energy harvester systems and methods thereof |
US7757811B2 (en) * | 2005-10-19 | 2010-07-20 | 3M Innovative Properties Company | Multilayer articles having acoustical absorbance properties and methods of making and using the same |
CZ305244B6 (en) * | 2005-11-10 | 2015-07-01 | Elmarco S.R.O. | Process for producing nanofibers by electrostatic spinning of solutions or melts of polymers and apparatus for making the same |
US7503326B2 (en) * | 2005-12-22 | 2009-03-17 | 3M Innovative Properties Company | Filtering face mask with a unidirectional valve having a stiff unbiased flexible flap |
US8325097B2 (en) * | 2006-01-14 | 2012-12-04 | Research In Motion Rf, Inc. | Adaptively tunable antennas and method of operation therefore |
US7390351B2 (en) | 2006-02-09 | 2008-06-24 | 3M Innovative Properties Company | Electrets and compounds useful in electrets |
US7601192B2 (en) * | 2006-06-07 | 2009-10-13 | Gore Enterprise Holdings, Inc. | Recirculation filter |
US7338355B2 (en) * | 2006-06-13 | 2008-03-04 | 3M Innovative Properties Company | Abrasive article and methods of making and using the same |
US9134471B2 (en) * | 2006-06-28 | 2015-09-15 | 3M Innovative Properties Company | Oriented polymeric articles and method |
US9139940B2 (en) | 2006-07-31 | 2015-09-22 | 3M Innovative Properties Company | Bonded nonwoven fibrous webs comprising softenable oriented semicrystalline polymeric fibers and apparatus and methods for preparing such webs |
US7902096B2 (en) * | 2006-07-31 | 2011-03-08 | 3M Innovative Properties Company | Monocomponent monolayer meltblown web and meltblowing apparatus |
US7807591B2 (en) * | 2006-07-31 | 2010-10-05 | 3M Innovative Properties Company | Fibrous web comprising microfibers dispersed among bonded meltspun fibers |
US7905973B2 (en) * | 2006-07-31 | 2011-03-15 | 3M Innovative Properties Company | Molded monocomponent monolayer respirator |
US7858163B2 (en) * | 2006-07-31 | 2010-12-28 | 3M Innovative Properties Company | Molded monocomponent monolayer respirator with bimodal monolayer monocomponent media |
US9770058B2 (en) * | 2006-07-17 | 2017-09-26 | 3M Innovative Properties Company | Flat-fold respirator with monocomponent filtration/stiffening monolayer |
US7947142B2 (en) * | 2006-07-31 | 2011-05-24 | 3M Innovative Properties Company | Pleated filter with monolayer monocomponent meltspun media |
US7754041B2 (en) * | 2006-07-31 | 2010-07-13 | 3M Innovative Properties Company | Pleated filter with bimodal monolayer monocomponent media |
RU2404306C2 (en) * | 2006-07-31 | 2010-11-20 | 3М Инновейтив Пропертиз Компани | Method of forming filtration articles |
US7628829B2 (en) * | 2007-03-20 | 2009-12-08 | 3M Innovative Properties Company | Abrasive article and method of making and using the same |
US20080233850A1 (en) * | 2007-03-20 | 2008-09-25 | 3M Innovative Properties Company | Abrasive article and method of making and using the same |
US20080271739A1 (en) | 2007-05-03 | 2008-11-06 | 3M Innovative Properties Company | Maintenance-free respirator that has concave portions on opposing sides of mask top section |
US20080271740A1 (en) | 2007-05-03 | 2008-11-06 | 3M Innovative Properties Company | Maintenance-free flat-fold respirator that includes a graspable tab |
US9770611B2 (en) | 2007-05-03 | 2017-09-26 | 3M Innovative Properties Company | Maintenance-free anti-fog respirator |
US20080314400A1 (en) * | 2007-05-31 | 2008-12-25 | Philip Morris Usa Inc. | Filter including electrostatically charged fiber material |
US7989371B2 (en) * | 2007-06-22 | 2011-08-02 | 3M Innovative Properties Company | Meltblown fiber web with staple fibers |
US20080315454A1 (en) * | 2007-06-22 | 2008-12-25 | 3M Innovative Properties Company | Method of making meltblown fiber web with staple fibers |
US7989372B2 (en) * | 2007-06-22 | 2011-08-02 | 3M Innovative Properties Company | Molded respirator comprising meltblown fiber web with staple fibers |
CN103801155B (en) * | 2007-07-26 | 2016-09-28 | 3M创新有限公司 | Highly charged and the nanometer fiber net of charge stable |
JP6032867B2 (en) * | 2007-07-26 | 2016-11-30 | スリーエム イノベイティブ プロパティズ カンパニー | Highly charged charge stable nanofiber web |
US8070862B2 (en) | 2007-09-04 | 2011-12-06 | 3M Innovative Properties Company | Dust collection device for sanding tool |
AU2008302589B2 (en) | 2007-09-20 | 2011-01-27 | 3M Innovative Properties Company | Filtering face-piece respirator that has expandable mask body |
WO2009062009A2 (en) * | 2007-11-09 | 2009-05-14 | Hollingsworth & Vose Company | Meltblown filter medium |
US8986432B2 (en) * | 2007-11-09 | 2015-03-24 | Hollingsworth & Vose Company | Meltblown filter medium, related applications and uses |
US8529671B2 (en) * | 2007-12-06 | 2013-09-10 | 3M Innovative Properties Comany | Electret webs with charge-enhancing additives |
US8491689B2 (en) * | 2007-12-21 | 2013-07-23 | 3M Innovative Properties Company | Joined filter media pleat packs |
CN101945692B (en) * | 2007-12-27 | 2013-07-10 | 3M创新有限公司 | Dust collection device for sanding tool |
BRPI0821434A2 (en) * | 2007-12-28 | 2015-06-16 | 3M Innovative Properties Co | Composite non-woven fibrous blankets and methods for preparing and using same |
WO2009088648A1 (en) * | 2007-12-31 | 2009-07-16 | 3M Innovative Properties Company | Composite non-woven fibrous webs having continuous particulate phase and methods of making and using the same |
CN101952210B (en) * | 2007-12-31 | 2013-05-29 | 3M创新有限公司 | Fluid filtration articles and methods of making and using the same |
BRPI0906008A2 (en) | 2008-02-21 | 2015-06-30 | 3M Innovative Properties Co | "Filter Media, Method for Making a Filter Media, Method for Removing Cyanogen Chloride from a Gas Flow, Filter Systems and Adduct" |
JP2009254418A (en) * | 2008-04-11 | 2009-11-05 | Three M Innovative Properties Co | Nose clip for mask, and mask |
US20110137082A1 (en) * | 2008-06-02 | 2011-06-09 | Li Fuming B | Charge-enhancing additives for electrets |
JP5676433B2 (en) * | 2008-06-02 | 2015-02-25 | スリーエム イノベイティブ プロパティズ カンパニー | Electret web with charge promoting additive |
US7765698B2 (en) * | 2008-06-02 | 2010-08-03 | 3M Innovative Properties Company | Method of making electret articles based on zeta potential |
AU2009257365A1 (en) * | 2008-06-12 | 2009-12-17 | 3M Innovative Properties Company | Melt blown fine fibers and methods of manufacture |
US8858986B2 (en) | 2008-06-12 | 2014-10-14 | 3M Innovative Properties Company | Biocompatible hydrophilic compositions |
EP2303770B1 (en) * | 2008-06-30 | 2014-07-09 | 3M Innovative Properties Company | Method for in situ formation of metal nanoclusters within a porous substrate |
DE102008047552A1 (en) * | 2008-09-16 | 2010-04-08 | Carl Freudenberg Kg | Electret filter element and method for its production |
US8057608B1 (en) | 2008-09-26 | 2011-11-15 | Research International, Inc | Extraction device and methods |
US11083916B2 (en) | 2008-12-18 | 2021-08-10 | 3M Innovative Properties Company | Flat fold respirator having flanges disposed on the mask body |
US8382872B2 (en) | 2008-12-23 | 2013-02-26 | 3M Innovative Properties Company | Dust collection device for sanding tool |
BRPI0923681A2 (en) | 2008-12-23 | 2016-01-19 | 3M Innovative Properties Co | "continuous spinning fibrous blankets endowed with a pattern and methods of preparation and use thereof". |
US8021996B2 (en) | 2008-12-23 | 2011-09-20 | Kimberly-Clark Worldwide, Inc. | Nonwoven web and filter media containing partially split multicomponent fibers |
EP2379785A1 (en) | 2008-12-30 | 2011-10-26 | 3M Innovative Properties Company | Elastic nonwoven fibrous webs and methods of making and using |
US8105409B2 (en) | 2009-01-30 | 2012-01-31 | General Electric Company | Filter retention system |
US8850719B2 (en) | 2009-02-06 | 2014-10-07 | Nike, Inc. | Layered thermoplastic non-woven textile elements |
US8906275B2 (en) | 2012-05-29 | 2014-12-09 | Nike, Inc. | Textured elements incorporating non-woven textile materials and methods for manufacturing the textured elements |
US20100199406A1 (en) * | 2009-02-06 | 2010-08-12 | Nike, Inc. | Thermoplastic Non-Woven Textile Elements |
US9682512B2 (en) | 2009-02-06 | 2017-06-20 | Nike, Inc. | Methods of joining textiles and other elements incorporating a thermoplastic polymer material |
US20100199520A1 (en) * | 2009-02-06 | 2010-08-12 | Nike, Inc. | Textured Thermoplastic Non-Woven Elements |
US20110290119A1 (en) | 2009-02-20 | 2011-12-01 | 3M Innovative Properties Company | Antimicrobial electret web |
BRPI1006777A2 (en) | 2009-03-31 | 2019-09-24 | 3M Innovative Properties Co | "blankets, article, surgical sheet, surgical gown, sterilization wrap, wound contact material and methods for making a blanket" |
US8048186B2 (en) | 2009-04-02 | 2011-11-01 | General Electric Company | Filter retention systems and devices |
US8790449B2 (en) | 2009-04-03 | 2014-07-29 | 3M Innovative Properties Company | Electret webs with charge-enhancing additives |
EP2414576B1 (en) | 2009-04-03 | 2016-11-09 | 3M Innovative Properties Company | Processing aids for webs, including electret webs |
US8950587B2 (en) | 2009-04-03 | 2015-02-10 | Hollingsworth & Vose Company | Filter media suitable for hydraulic applications |
US20100252047A1 (en) * | 2009-04-03 | 2010-10-07 | Kirk Seth M | Remote fluorination of fibrous filter webs |
ITPD20090117A1 (en) * | 2009-05-04 | 2010-11-05 | Euroflex Srl | HAND SPRAYER FOR DETERGENT LIQUIDS |
JP2010268346A (en) | 2009-05-18 | 2010-11-25 | Sharp Corp | Image forming apparatus displaying information related to function combined with one function |
JP4875726B2 (en) | 2009-05-18 | 2012-02-15 | シャープ株式会社 | Information processing apparatus for processing information on functions combined with one function and image forming apparatus including the information processing apparatus |
JP4875727B2 (en) * | 2009-05-18 | 2012-02-15 | シャープ株式会社 | Information processing apparatus for processing information on functions combined with one function and image forming apparatus including the information processing apparatus |
KR101800034B1 (en) | 2009-09-01 | 2017-11-21 | 쓰리엠 이노베이티브 프로퍼티즈 컴파니 | Apparatus, system, and method for forming nanofibers and nanofiber webs |
ES2676296T3 (en) | 2009-09-11 | 2018-07-18 | Breathe Safely Inc. | Passive disposable filtering face mask with gasket inside gasket and gasket with optional bridge |
EP2298096A2 (en) | 2009-09-18 | 2011-03-23 | 3M Innovative Properties Co. | Filtering face respirator having grasping feature indicator |
US8881729B2 (en) | 2009-09-18 | 2014-11-11 | 3M Innovative Properties Company | Horizontal flat-fold filtering face-piece respirator having indicia of symmetry |
US8640704B2 (en) | 2009-09-18 | 2014-02-04 | 3M Innovative Properties Company | Flat-fold filtering face-piece respirator having structural weld pattern |
US8534294B2 (en) | 2009-10-09 | 2013-09-17 | Philip Morris Usa Inc. | Method for manufacture of smoking article filter assembly including electrostatically charged fiber |
US8528560B2 (en) | 2009-10-23 | 2013-09-10 | 3M Innovative Properties Company | Filtering face-piece respirator having parallel line weld pattern in mask body |
EP2501440A2 (en) | 2009-11-18 | 2012-09-26 | 3M Innovative Properties Company | Reinforced filter media |
KR101800906B1 (en) | 2009-11-24 | 2017-11-23 | 쓰리엠 이노베이티브 프로퍼티즈 컴파니 | Articles and methods using shape-memory polymers |
US8365771B2 (en) | 2009-12-16 | 2013-02-05 | 3M Innovative Properties Company | Unidirectional valves and filtering face masks comprising unidirectional valves |
EP2512802B1 (en) * | 2009-12-17 | 2017-12-13 | 3M Innovative Properties Company | Dimensionally stable nonwoven fibrous webs and methods of making and using the same |
MX2012007090A (en) | 2009-12-17 | 2012-07-20 | 3M Innovative Properties Co | Dimensionally stable nonwoven fibrous webs, melt blown fine fibers, and methods of making and using the same. |
EP2519326A4 (en) | 2009-12-30 | 2016-08-24 | 3M Innovative Properties Co | Filtering face-piece respirator having an auxetic mesh in the mask body |
CA2786867C (en) | 2010-01-18 | 2022-01-04 | 3M Innovative Properties Company | Air filter with sorbent particles |
AU2011218854B2 (en) | 2010-02-23 | 2015-03-12 | 3M Innovative Properties Company | Dimensionally stable nonwoven fibrous webs and methods of making and using the same |
US8087492B2 (en) * | 2010-03-08 | 2012-01-03 | Huntair, Inc. | Methods and systems for integrating sound attenuation into a filter bank |
CN102859058B (en) | 2010-04-22 | 2016-03-23 | 3M创新有限公司 | The method of the nonwoven web containing chemism particle and manufacture and the described nonwoven web of use |
EP2561127B1 (en) | 2010-04-22 | 2015-01-21 | 3M Innovative Properties Company | Nonwoven nanofiber webs containing chemically active particulates and methods of making and using same |
US8679218B2 (en) | 2010-04-27 | 2014-03-25 | Hollingsworth & Vose Company | Filter media with a multi-layer structure |
JP5475541B2 (en) * | 2010-05-07 | 2014-04-16 | 日本バイリーン株式会社 | Charging filter and mask |
US20120017911A1 (en) | 2010-07-26 | 2012-01-26 | 3M Innovative Properties Company | Filtering face-piece respirator having foam shaping layer |
CA2809200C (en) | 2010-08-23 | 2019-09-17 | Fiberweb Corovin Gmbh | Nonwoven web and fibers with electret properties, manufacturing processes thereof and their use |
TW201221714A (en) | 2010-10-14 | 2012-06-01 | 3M Innovative Properties Co | Dimensionally stable nonwoven fibrous webs and methods of making and using the same |
US8585808B2 (en) | 2010-11-08 | 2013-11-19 | 3M Innovative Properties Company | Zinc oxide containing filter media and methods of forming the same |
US20120125341A1 (en) | 2010-11-19 | 2012-05-24 | 3M Innovative Properties Company | Filtering face-piece respirator having an overmolded face seal |
US10155186B2 (en) | 2010-12-17 | 2018-12-18 | Hollingsworth & Vose Company | Fine fiber filter media and processes |
US20120152821A1 (en) | 2010-12-17 | 2012-06-21 | Hollingsworth & Vose Company | Fine fiber filter media and processes |
RU2477540C2 (en) * | 2011-04-11 | 2013-03-10 | Государственное образовательное учреждение высшего профессионального образования "Российский государственный педагогический университет им. А.И. Герцена" | Method of film electret production |
EP2726659B1 (en) | 2011-06-30 | 2020-11-11 | 3M Innovative Properties Company | Non-woven electret fibrous webs and methods of making same |
KR20140068041A (en) | 2011-08-01 | 2014-06-05 | 쓰리엠 이노베이티브 프로퍼티즈 캄파니 | Respiratory assembly including latching mechanism |
US9700743B2 (en) | 2012-07-31 | 2017-07-11 | 3M Innovative Properties Company | Respiratory assembly including latching mechanism |
TW201339387A (en) | 2011-12-16 | 2013-10-01 | Toray Industries | Combined filament nonwoven fabric, laminated sheet, filter and process for manufacturing the combined filament nonwoven fabric |
US20130255103A1 (en) | 2012-04-03 | 2013-10-03 | Nike, Inc. | Apparel And Other Products Incorporating A Thermoplastic Polymer Material |
WO2014059239A1 (en) | 2012-10-12 | 2014-04-17 | 3M Innovative Properties Company | Multi-layer articles |
US11116998B2 (en) | 2012-12-27 | 2021-09-14 | 3M Innovative Properties Company | Filtering face-piece respirator having folded flange |
US10182603B2 (en) | 2012-12-27 | 2019-01-22 | 3M Innovative Properties Company | Filtering face-piece respirator having strap-activated folded flange |
PL2938420T3 (en) | 2012-12-28 | 2018-07-31 | 3M Innovative Properties Company | Electret webs with charge-enhancing additives |
US9408424B2 (en) | 2013-01-10 | 2016-08-09 | 3M Innovative Properties Company | Filtering face-piece respirator having a face seal comprising a water-vapor-breathable layer |
US9510626B2 (en) | 2013-02-01 | 2016-12-06 | 3M Innovative Properties Company | Sleeve-fit respirator cartridge |
KR102116776B1 (en) | 2013-04-11 | 2020-05-29 | 도레이 카부시키가이샤 | Mixed-fiber nonwoven fabric and method for manufacturing same |
BR112015026517A2 (en) | 2013-04-19 | 2017-07-25 | 3M Innovative Properties Co | electret blankets with charge enhancing additives |
US9694306B2 (en) | 2013-05-24 | 2017-07-04 | Hollingsworth & Vose Company | Filter media including polymer compositions and blends |
EP2835163B1 (en) * | 2013-08-09 | 2016-10-12 | Eurofilters N.V. | Filter bag for a vacuum cleaner and a method for determining a surface of a vacuum cleaner dust bag which is directly impacted by the air flow |
RU2528618C1 (en) * | 2013-11-19 | 2014-09-20 | федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Российский государственный педагогический университет им. А.И. Герцена" (РГПУ им. А.И. Герцена) | Method of film electret production |
EP3074559B1 (en) | 2013-11-26 | 2020-09-02 | 3M Innovative Properties Company | Dimensionally-stable melt blown nonwoven fibrous structures, and methods and apparatus for making same |
KR20170034447A (en) | 2013-12-17 | 2017-03-28 | 쓰리엠 이노베이티브 프로퍼티즈 컴파니 | Air quality indicator |
EP3110275B1 (en) | 2014-02-27 | 2019-01-09 | 3M Innovative Properties Company | Respirator having elastic straps having openwork structure |
EP3110525A4 (en) | 2014-02-28 | 2018-03-21 | 3M Innovative Properties Company | Filtration medium including polymeric netting of ribbons and strands |
US10040621B2 (en) | 2014-03-20 | 2018-08-07 | 3M Innovative Properties Company | Filtering face-piece respirator dispenser |
KR20170021853A (en) | 2014-06-23 | 2017-02-28 | 쓰리엠 이노베이티브 프로퍼티즈 캄파니 | Electret webs with charge-enhancing additives |
JP2017525862A (en) | 2014-08-18 | 2017-09-07 | スリーエム イノベイティブ プロパティズ カンパニー | Respirator comprising a polymer net and method for forming a respirator comprising a polymer net |
PL3186425T3 (en) | 2014-08-26 | 2020-05-18 | 3M Innovative Properties Company | Spunbonded web comprising polylactic acid fibers |
WO2016069342A1 (en) | 2014-10-31 | 2016-05-06 | 3M Innovative Properties Company | Respirator having corrugated filtering structure |
DE112015005693A5 (en) * | 2014-12-18 | 2017-08-31 | Oerlikon Textile Gmbh & Co. Kg | Device for charging a fibrous web |
US10343095B2 (en) | 2014-12-19 | 2019-07-09 | Hollingsworth & Vose Company | Filter media comprising a pre-filter layer |
US10201198B2 (en) * | 2014-12-23 | 2019-02-12 | Profit Royal Pharmaceutical Limited | Protective masks with coating comprising different electrospun fibers interweaved with each other, formulations forming the same, and method of producing thereof |
KR102466690B1 (en) * | 2015-03-16 | 2022-11-14 | 도레이 카부시키가이샤 | electret fiber sheet |
GB201508114D0 (en) | 2015-05-12 | 2015-06-24 | 3M Innovative Properties Co | Respirator tab |
US10669481B2 (en) | 2015-07-07 | 2020-06-02 | 3M Innovative Properties Company | Substituted benzotriazole phenolate salts and antioxidant compositions formed therefrom |
JP6987739B2 (en) | 2015-07-07 | 2022-01-05 | スリーエム イノベイティブ プロパティズ カンパニー | Polymer matrix with ionic additives |
CA2991412A1 (en) | 2015-07-07 | 2017-01-12 | 3M Innovative Properties Company | Substituted benzotriazole phenols |
EP3320135B1 (en) | 2015-07-07 | 2019-08-28 | 3M Innovative Properties Company | Electret webs with charge-enhancing additives |
RU2015141569A (en) | 2015-09-30 | 2017-04-05 | 3М Инновейтив Пропертиз Компани | FOLDING RESPIRATOR WITH FACE MASK AND EXHAUST VALVE |
WO2017066284A1 (en) | 2015-10-12 | 2017-04-20 | 3M Innovative Properties Company | Filtering face-piece respirator including functional material and method of forming same |
CA2928138A1 (en) | 2015-11-10 | 2017-05-10 | 3M Innovative Properties Company | Air filter use indicators |
EP3374035B1 (en) | 2015-11-11 | 2020-12-23 | 3M Innovative Properties Company | Shape retaining flat-fold respirator |
EP3396058A4 (en) * | 2015-12-22 | 2019-08-28 | Toray Industries, Inc. | Electret fiber sheet |
US11000827B2 (en) | 2016-03-14 | 2021-05-11 | 3M Innovative Properties Company | Air filters comprising polymeric sorbents for reactive gases |
US10960341B2 (en) | 2016-03-14 | 2021-03-30 | 3M Innovative Properties Company | Air filters comprising polymeric sorbents for aldehydes |
US11014070B2 (en) | 2016-03-14 | 2021-05-25 | 3M Innovative Properties Company | Composite granules including polymeric sorbent for reactive gases |
CA3018596C (en) | 2016-03-24 | 2024-01-23 | 3M Innovative Properties Company | Room air purifier with rfid reader |
KR20190040275A (en) * | 2016-08-26 | 2019-04-17 | 쓰리엠 이노베이티브 프로퍼티즈 컴파니 | Improved indoor air purifiers and filtration media |
US10119469B2 (en) | 2016-09-15 | 2018-11-06 | General Electric Company | Method and apparatus for modularized inlet silencer baffles |
US10722990B2 (en) | 2016-09-15 | 2020-07-28 | General Electric Company | Method for installing and removing modularized silencer baffles |
KR102558116B1 (en) | 2016-09-16 | 2023-07-21 | 쓰리엠 이노베이티브 프로퍼티즈 캄파니 | Exhalation valve and respirator including the same |
DE102016119480A1 (en) * | 2016-10-12 | 2018-04-12 | TRüTZSCHLER GMBH & CO. KG | Nozzle bar for processing fibers with water jets |
MX2019004911A (en) | 2016-10-28 | 2019-06-12 | 3M Innovative Properties Co | Respirator including reinforcing element. |
KR20190077528A (en) | 2016-11-14 | 2019-07-03 | 쓰리엠 이노베이티브 프로퍼티즈 캄파니 | An air filter comprising a metal-containing polymer sorbent |
JP2018095973A (en) | 2016-12-08 | 2018-06-21 | 東レ株式会社 | Melt-blown nonwoven fabric |
CN110446541B (en) | 2017-01-05 | 2021-12-03 | 3M创新有限公司 | Electret webs with charge-enhancing additives |
CN108278157B (en) | 2017-01-06 | 2022-08-02 | 通用电气公司 | System and method for improved inlet silencer baffle |
CN108278158B (en) | 2017-01-06 | 2022-05-13 | 通用电气公司 | System and method for improved inlet muffling baffle |
US20180243674A1 (en) * | 2017-02-21 | 2018-08-30 | Hollingsworth & Vose Company | Electret-containing filter media |
RU2671037C2 (en) | 2017-03-17 | 2018-10-29 | 3М Инновейтив Пропертиз Компани | Foldable filter respirator with a face mask ffp3 |
CN106964199B (en) * | 2017-05-04 | 2022-08-09 | 浙江金海高科股份有限公司 | Liquid charging method and device for electret material |
US11278832B2 (en) | 2017-06-16 | 2022-03-22 | 3M Innovative Properties Company | Air filters comprising polymeric sorbents for aldehydes |
WO2019012399A1 (en) | 2017-07-14 | 2019-01-17 | 3M Innovative Properties Company | Adapter for conveying plural liquid streams |
EP3732251A4 (en) | 2017-12-28 | 2021-09-15 | 3M Innovative Properties Company | Ceramic-coated fibers including a flame-retarding polymer, and methods of making nonwoven structures |
JP7255477B2 (en) | 2018-02-15 | 2023-04-11 | 東レ株式会社 | Nonwoven fabric and air filter medium using the same |
US11491760B2 (en) | 2018-03-13 | 2022-11-08 | Mitsui Chemicals, Inc. | Breathable sheet, laminate, and composite |
CN112218981A (en) | 2018-05-17 | 2021-01-12 | 田纳西大学研究基金会 | Method for saturating a nonwoven fabric with a liquid and method for producing an electret therefor |
CN113710344A (en) | 2019-05-01 | 2021-11-26 | 奥升德功能材料运营有限公司 | Filter media comprising a polyamide nanofiber layer |
EP3990686B1 (en) | 2019-06-26 | 2024-01-03 | 3M Innovative Properties Company | Method of making a nonwoven fiber web, and a nonwoven fiber web |
KR20220024679A (en) * | 2019-06-28 | 2022-03-03 | 쓰리엠 이노베이티브 프로퍼티즈 캄파니 | Core-Sheath Fibers, Nonwoven Fibrous Webs, and Respirators Containing Same |
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EP4045167A1 (en) | 2019-10-16 | 2022-08-24 | 3M Innovative Properties Company | Dual-function melt additives |
WO2021074746A1 (en) | 2019-10-16 | 2021-04-22 | 3M Innovative Properties Company | Substituted benzimidazole melt additives |
CN110820174B (en) * | 2019-11-20 | 2021-05-28 | 邯郸恒永防护洁净用品有限公司 | Electret equipment of polypropylene melt-blown non-woven fabric |
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US20220410045A1 (en) | 2019-12-03 | 2022-12-29 | 3M Innovative Properties Company | Thiolate salt melt additives |
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DE102020107746A1 (en) | 2020-03-20 | 2021-09-23 | Solvamed Gmbh | Improved respirator |
WO2021194189A1 (en) * | 2020-03-26 | 2021-09-30 | 도레이첨단소재 주식회사 | Method for manufacturing composite non-woven fabric, composite non-woven fabric, and article |
US11219255B2 (en) | 2020-04-08 | 2022-01-11 | Terry Earl Brady | Self-contained, mobile breathing apparatus or appliance that supplies pathogen and endotoxin free, rhythmically breathable air to the wearer or treated space through active, continuous bio-deactivation and destruction of bacteria, fungi, viral and allergenic/antigenic matter safely when using benign, household, rechargeable filtration media |
RU200604U1 (en) * | 2020-04-17 | 2020-10-30 | Владимир Владимирович Зайцев | Respiratory protection filtering agent |
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US20230233966A1 (en) | 2020-06-30 | 2023-07-27 | Toray Industries, Inc. | Electret fiber sheet, laminate sheet, and filter |
US11918747B2 (en) * | 2020-07-27 | 2024-03-05 | Cullen Thomas Moore | Bioburden reduction surgical masks/respirators with use in protection against SARS-CoV-2 infections |
US11786853B2 (en) | 2020-08-10 | 2023-10-17 | F.N. Smith Corporation | Facepiece electrostatic charging devices and methods thereof |
WO2022034437A1 (en) | 2020-08-11 | 2022-02-17 | 3M Innovative Properties Company | Electret webs with carboxylic acid or carboxylate salt charge-enhancing additives |
US20230285884A1 (en) | 2020-08-11 | 2023-09-14 | 3M Innovative Properties Company | Electret webs with benzoate salt charge-enhancing additives |
JPWO2022075381A1 (en) | 2020-10-07 | 2022-04-14 | ||
EP4237601A1 (en) | 2020-11-02 | 2023-09-06 | 3M Innovative Properties Company | Core-sheath fibers, nonwoven fibrous web, and filtering articles including the same |
WO2022118104A1 (en) | 2020-12-01 | 2022-06-09 | 3M Innovative Properties Company | Article for storage of bacteriophages and method thereof |
US20240009606A1 (en) | 2020-12-18 | 2024-01-11 | 3M Innovative Properties Company | Electrets comprising a substituted cyclotriphosphazene compound and articles therefrom |
CN112870850A (en) * | 2020-12-29 | 2021-06-01 | 广东金发科技有限公司 | Antibacterial melt-blown material and preparation method and application thereof |
CN113026207A (en) * | 2021-02-04 | 2021-06-25 | 稳健医疗(武汉)有限公司 | Spray-melting cloth spray-melting production method and production system thereof |
WO2023031697A1 (en) | 2021-09-01 | 2023-03-09 | 3M Innovative Properties Company | Anti-virus respirator and mask |
WO2023063298A1 (en) * | 2021-10-13 | 2023-04-20 | 東洋紡株式会社 | Method for producing poly-4-methyl-1-pentene of lower molecular weight |
CN114504951B (en) * | 2022-01-24 | 2023-09-22 | 华南理工大学 | Recyclable electret filter membrane and preparation method, cleaning and charge regeneration method thereof |
DE102022000777A1 (en) | 2022-03-04 | 2023-09-07 | Oerlikon Textile Gmbh & Co. Kg | Process and device for the production of electrostatically charged fibers and electret product |
US20240115889A1 (en) | 2022-10-07 | 2024-04-11 | 3M Innovative Properties Company | Disposable, Flat-Fold Respirator Having Increased Stiffness in Selected Areas |
Family Cites Families (48)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US30782A (en) * | 1860-11-27 | John wright | ||
US31285A (en) * | 1861-01-29 | Making- finger-guards for harvesters | ||
NL271149A (en) * | 1960-11-08 | 1900-01-01 | ||
US3493462A (en) * | 1962-07-06 | 1970-02-03 | Du Pont | Nonpatterned,nonwoven fabric |
US3416714A (en) * | 1966-07-05 | 1968-12-17 | Phillips Petroleum Co | Method of fibrillation |
US3562771A (en) * | 1967-10-20 | 1971-02-09 | Du Pont | Process for preparation of continuous filament nonwoven webs |
DE1944548C3 (en) * | 1969-09-02 | 1980-04-03 | Laerdal, Asmund S., Stavanger (Norwegen) | Collapsible ventilation mask and transport bag therefor |
US3971373A (en) * | 1974-01-21 | 1976-07-27 | Minnesota Mining And Manufacturing Company | Particle-loaded microfiber sheet product and respirators made therefrom |
NL160303C (en) * | 1974-03-25 | 1979-10-15 | Verto Nv | METHOD FOR MANUFACTURING A FIBER FILTER |
US4100324A (en) * | 1974-03-26 | 1978-07-11 | Kimberly-Clark Corporation | Nonwoven fabric and method of producing same |
US4188690A (en) * | 1976-02-25 | 1980-02-19 | Mitsubishi Rayon Company, Limited | Nonwoven fabric and manufacturing method thereof |
CA1073648A (en) * | 1976-08-02 | 1980-03-18 | Edward R. Hauser | Web of blended microfibers and crimped bulking fibers |
US4146663A (en) * | 1976-08-23 | 1979-03-27 | Asahi Kasei Kogyo Kabushiki Kaisha | Composite fabric combining entangled fabric of microfibers and knitted or woven fabric and process for producing same |
NL181632C (en) * | 1976-12-23 | 1987-10-01 | Minnesota Mining & Mfg | ELECTRIC FILTER AND METHOD FOR MANUFACTURING THAT. |
US4215682A (en) | 1978-02-06 | 1980-08-05 | Minnesota Mining And Manufacturing Company | Melt-blown fibrous electrets |
JPS55138223A (en) | 1979-04-12 | 1980-10-28 | Tokyo Shibaura Electric Co | Method of manufacturing electret |
FR2480807A1 (en) * | 1980-04-18 | 1981-10-23 | Seplast Sa | PROCESS FOR THE SUPERFICIAL TREATMENT OF A FIBROUS, NON-WOVEN AND VERY ACOUSTIC FILTERING LAYER, FORMING ELECTRET AND ITS APPLICATION TO FILTERS AND RESPIRATORY MASKS, IN PARTICULAR |
US4375718A (en) * | 1981-03-12 | 1983-03-08 | Surgikos, Inc. | Method of making fibrous electrets |
US4429001A (en) * | 1982-03-04 | 1984-01-31 | Minnesota Mining And Manufacturing Company | Sheet product containing sorbent particulate material |
DE3381143D1 (en) * | 1982-03-31 | 1990-03-01 | Toray Industries | ULTRA FINE KINDED FIBERS FIBERS, AND METHOD FOR PRODUCING THE SAME. |
US4548628A (en) * | 1982-04-26 | 1985-10-22 | Asahi Kasei Kogyo Kabushiki Kaisha | Filter medium and process for preparing same |
WO1984003193A1 (en) * | 1983-02-04 | 1984-08-16 | Minnesota Mining & Mfg | Method and apparatus for manufacturing an electret filter medium |
US4729371A (en) * | 1983-10-11 | 1988-03-08 | Minnesota Mining And Manufacturing Company | Respirator comprised of blown bicomponent fibers |
US4944854A (en) * | 1983-11-08 | 1990-07-31 | Celanese Corporation | Electret process and products |
JPS60168511A (en) * | 1984-02-10 | 1985-09-02 | Japan Vilene Co Ltd | Production of electret filter |
JPS60225416A (en) * | 1984-04-24 | 1985-11-09 | 三井化学株式会社 | High performance electret and air filter |
US4874659A (en) * | 1984-10-24 | 1989-10-17 | Toray Industries | Electret fiber sheet and method of producing same |
GB2176404B (en) * | 1985-06-13 | 1988-07-27 | Od G Univ Im I I Mechnikova | Respirator |
US5078132A (en) * | 1985-08-28 | 1992-01-07 | Minnesota Mining And Manufacturing Company | Bonded adsorbent structures and respirators incorporating same |
US4612237A (en) * | 1985-12-13 | 1986-09-16 | E. I. Du Pont De Nemours And Company | Hydraulically entangled PTFE/glass filter felt |
JPS62263361A (en) * | 1986-05-09 | 1987-11-16 | 東レ株式会社 | Production of nonwoven fabric |
DE3719420A1 (en) * | 1987-06-11 | 1988-12-29 | Sandler Helmut Helsa Werke | RESPIRATORY MASK |
US4775579A (en) * | 1987-11-05 | 1988-10-04 | James River Corporation Of Virginia | Hydroentangled elastic and nonelastic filaments |
DE3839956C2 (en) * | 1987-11-28 | 1998-07-02 | Toyo Boseki | Electret film and process for its production |
US4874399A (en) * | 1988-01-25 | 1989-10-17 | Minnesota Mining And Manufacturing Company | Electret filter made of fibers containing polypropylene and poly(4-methyl-1-pentene) |
US4886058A (en) * | 1988-05-17 | 1989-12-12 | Minnesota Mining And Manufacturing Company | Filter element |
US4917942A (en) * | 1988-12-22 | 1990-04-17 | Minnesota Mining And Manufacturing Company | Nonwoven filter material |
US5028465A (en) * | 1989-03-20 | 1991-07-02 | James River Corporation | Hydroentangled composite filter element |
CA2027687C (en) * | 1989-11-14 | 2002-12-31 | Douglas C. Sundet | Filtration media and method of manufacture |
CA2037942A1 (en) * | 1990-03-12 | 1991-09-13 | Satoshi Matsuura | Process for producing an electret, a film electret, and an electret filter |
JPH04330907A (en) * | 1991-05-02 | 1992-11-18 | Mitsui Petrochem Ind Ltd | Manufacture of electret filter |
US5227172A (en) * | 1991-05-14 | 1993-07-13 | Exxon Chemical Patents Inc. | Charged collector apparatus for the production of meltblown electrets |
US5207970A (en) * | 1991-09-30 | 1993-05-04 | Minnesota Mining And Manufacturing Company | Method of forming a web of melt blown layered fibers |
JP3070632B2 (en) * | 1991-11-21 | 2000-07-31 | ユニチカ株式会社 | Flexible nonwoven fabric and method for producing the same |
US5244482A (en) * | 1992-03-26 | 1993-09-14 | The University Of Tennessee Research Corporation | Post-treatment of nonwoven webs |
US5280406A (en) * | 1992-06-18 | 1994-01-18 | International Business Machines Corporation | Jet deposition of electrical charge on a dielectric surface |
AU669420B2 (en) * | 1993-03-26 | 1996-06-06 | Minnesota Mining And Manufacturing Company | Oily mist resistant electret filter media |
DE69417041T2 (en) * | 1993-08-17 | 1999-07-15 | Minnesota Mining & Mfg | METHOD FOR CHARGING ELECTRIC FILTER MEDIA |
-
1994
- 1994-08-17 DE DE69417041T patent/DE69417041T2/en not_active Expired - Lifetime
- 1994-08-17 CA CA002168126A patent/CA2168126C/en not_active Expired - Fee Related
- 1994-08-17 US US08/291,611 patent/US5496507A/en not_active Expired - Lifetime
- 1994-08-17 AU AU79532/94A patent/AU680561B2/en not_active Ceased
- 1994-08-17 CN CN94193221A patent/CN1052042C/en not_active Expired - Fee Related
- 1994-08-17 KR KR1019960700679A patent/KR100336012B1/en not_active IP Right Cessation
- 1994-08-17 JP JP50715795A patent/JP3476084B2/en not_active Expired - Fee Related
- 1994-08-17 ES ES97122147T patent/ES2336163T3/en not_active Expired - Lifetime
- 1994-08-17 RU RU96105995A patent/RU2130521C1/en not_active IP Right Cessation
- 1994-08-17 EP EP97122147A patent/EP0845554B1/en not_active Expired - Lifetime
- 1994-08-17 BR BR9407259A patent/BR9407259A/en not_active IP Right Cessation
- 1994-08-17 ES ES94930403T patent/ES2128590T3/en not_active Expired - Lifetime
- 1994-08-17 PL PL94312993A patent/PL173854B1/en not_active IP Right Cessation
- 1994-08-17 WO PCT/US1994/009275 patent/WO1995005501A2/en active IP Right Grant
- 1994-08-17 DE DE69435251T patent/DE69435251D1/en not_active Expired - Lifetime
- 1994-08-17 EP EP94930403A patent/EP0714463B1/en not_active Expired - Lifetime
-
1997
- 1997-05-29 US US08/865,362 patent/US6119691A/en not_active Expired - Lifetime
- 1997-09-02 US US09/111,833 patent/US6783574B1/en not_active Expired - Fee Related
-
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- 2003-07-03 JP JP2003191177A patent/JP3735687B2/en not_active Expired - Fee Related
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106245230A (en) * | 2016-08-31 | 2016-12-21 | 侯慕毅 | A kind of heat-insulating and sound-absorbing material and forming method thereof and special shaping device |
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JP2004074149A (en) | 2004-03-11 |
EP0714463A1 (en) | 1996-06-05 |
KR100336012B1 (en) | 2002-10-11 |
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AU680561B2 (en) | 1997-07-31 |
JP3476084B2 (en) | 2003-12-10 |
PL173854B1 (en) | 1998-05-29 |
US6119691A (en) | 2000-09-19 |
EP0845554A3 (en) | 2000-09-27 |
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WO1995005501A2 (en) | 1995-02-23 |
CA2168126A1 (en) | 1995-02-23 |
DE69435251D1 (en) | 2009-12-31 |
PL312993A1 (en) | 1996-05-27 |
US6783574B1 (en) | 2004-08-31 |
AU7953294A (en) | 1995-03-14 |
EP0714463B1 (en) | 1999-03-10 |
CN1129963A (en) | 1996-08-28 |
JP3735687B2 (en) | 2006-01-18 |
RU2130521C1 (en) | 1999-05-20 |
ES2128590T3 (en) | 1999-05-16 |
DE69417041D1 (en) | 1999-04-15 |
BR9407259A (en) | 1996-09-24 |
CN1052042C (en) | 2000-05-03 |
EP0845554A2 (en) | 1998-06-03 |
US5496507A (en) | 1996-03-05 |
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