New! View global litigation for patent families

USRE31285E - Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method - Google Patents

Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method Download PDF

Info

Publication number
USRE31285E
USRE31285E US06328027 US32802781A USRE31285E US RE31285 E USRE31285 E US RE31285E US 06328027 US06328027 US 06328027 US 32802781 A US32802781 A US 32802781A US RE31285 E USRE31285 E US RE31285E
Authority
US
Grant status
Grant
Patent type
Prior art keywords
filter
foil
fibers
method
according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06328027
Inventor
Jan van Turnhout
Johannes C. Rieke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Co
Original Assignee
3M Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • DTEXTILES; PAPER
    • D04BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04HMAKING 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
    • D04H13/00Other non-woven fabrics
    • D04H13/02Production of non-woven fabrics by partial defibrillation of oriented thermoplastics films
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D39/00Filtering material for liquid or gaseous fluids
    • B01D39/14Other self-supporting filtering material ; Other filtering material
    • B01D39/16Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/1607Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
    • B01D39/1623Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
    • B01D39/163Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin sintered or bonded
    • DTEXTILES; PAPER
    • D04BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04HMAKING 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
    • D04H1/00Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/04Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres having existing or potential cohesive properties, e.g. natural fibres, prestretched or fibrillated artificial fibres
    • D04H1/06Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres having existing or potential cohesive properties, e.g. natural fibres, prestretched or fibrillated artificial fibres by treatment to produce shrinking, swelling, crimping or curling of fibres
    • DTEXTILES; PAPER
    • D04BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04HMAKING 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
    • D04H1/00Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40Non-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
    • D04H1/42Non-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
    • D04H1/4282Addition polymers
    • D04H1/4291Olefin series
    • DTEXTILES; PAPER
    • D04BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04HMAKING 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
    • D04H1/00Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40Non-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
    • D04H1/42Non-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
    • D04H1/4382Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
    • DTEXTILES; PAPER
    • D04BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04HMAKING 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
    • D04H13/00Other non-woven fabrics
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2239/00Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/04Additives and treatments of the filtering material
    • B01D2239/0435Electret
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2239/00Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/0604Arrangement of the fibres in the filtering material
    • B01D2239/0636Two or more types of fibres present in the filter material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2239/00Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/06Filter cloth, e.g. knitted, woven non-woven; self-supported material
    • B01D2239/069Special geometry of layers
    • B01D2239/0695Wound layers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2239/00Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/10Filtering material manufacturing
    • YGENERAL 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
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S264/00Plastic and nonmetallic article shaping or treating: processes
    • Y10S264/48Processes of making filters
    • YGENERAL 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
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S55/00Gas separation
    • Y10S55/05Methods of making filter
    • YGENERAL 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
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S55/00Gas separation
    • Y10S55/39Electrets separator
    • YGENERAL 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
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/29Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913Rod, strand, filament or fiber
    • Y10T428/2922Nonlinear [e.g., crimped, coiled, etc.]

Abstract

A method for forming a filter of electrically charged electret fiber material, consisting of a high molecular weight, nonpolar polymeric substance, comprising drawing, charging, and fibrillating a foil of said high molecular weight substance. The fibrillated foil is wound and then crimping is effected.

Description

The invention is related to a method for manufacturing a filter of electrically charged electret fiber material, consisting of a highmolecular non-polar substance, comprising the continuous supply of a foil of said substance, the drawing, charging and fibrillating of the foil and the processing of the thus fiber material into a filter.

Such a method is known. However, it appeared that in the filters obtained according to said method the coherence in the fiber mass is often insufficient in particular for that application in which the filter has to endure mechanical vibrations or is mechanically loaded in another way. Moreover, the filter effect does not satisfy completely the expectations because of the fact, that the penetration in a high loading with dust increases too rapidly.

The invention aimes to provide a method for manufacturing a filter with which such a structure of the filter is obtained, that mechanical as well as filtering characteristics of the filter satisfy high demands.

To obtain this, the method according to the invention is characterized in that by a suitable choice of the foil and/or by the type of drawing, crimpable fiber material is manufactured, this is wound in uncrimped condition to a fibrous package and that subsequently the crimping is effected.

By having the fibers crimped after being made into a package, in which they already have a certain mutual coherence, the fibers interlock and strengthen their coherence with the result that they form a firm filter which appears to stand a mechanical loading. Moreover, it appears that the pores of the filter have become more erratic concerning their shape and have become more uniform in measure and distribution; by this the catching of dust by the charged fibers is improved, as appears from a lower penetration and therefore a better functioning of the filter.

To be able to wind the fiber material in a not-crimped condition to a fiber package, the foil is during fibrillation as well as the netlike fiber fleece, obtained by this, slightly tensioned during winding, by which the spontaneous tendency to crimp of the fibers is oppressed.

After the fiber package of the desired volume is wound, it is taken from the winding means for instance by cutting it in the axial direction. The tension, with which it is wound, then falls off so the crimping of the fibers takes place.

To strengthen the crimp and also to fix the crimp and with that the coherence of the fibers according to a preferred embodiment of the method according to the invention. The filter is subjected to a heat treatment, for instance by putting it during about 15 minutes in an oven at about 70° C.

The filter may, if necessary, still further be consolidated and compacted by subjecting it to a needle treatment.

The crimpability of the fibers is according to a further feature of the invention obtained in that a foil is used in which at least two substances with different drawing- or crimping characteristics are incorporated in a non-homogeneous mixture.

According to a preferred embodiment of the method a foil is used being a laminate of said substances. The crimping characteristics of the thus obtained fibers are more uniform and reproducable, so it is avoided that the filter has weak parts or parts being too pervious. The draw- or crimp characteristics of the used substances may differ as result of the fact that the substances are of different type. However, they also can be of the same type; the difference in characteristics then are caused by a difference in molecular weight of or admixtures, or in the case of a laminate by the fact that the substance of the one layer is predrawn and that of the other layer is not drawn or not drawn in the same measure.

In another embodiment of the method according to the invention, the crimpability of the fibers is obtained or improved by the fact that the foil during or after drawing is deformed strongly for instance by moving it over a sharp edge.

The invention is also related to filters manufactured according to the above method. These filters differ with regard to known filters in that they have better mechanical characteristics, an improved homogenity and an improved filter action. They are in particular suited for those applications in which the catching of bacteria is of importance, such as ventilation systems for operating rooms and laboratories as face masks, and as a filter in suction cleaners, either as a dust bag or as a discharge filter. Moreover, they have the advantage that they are more resilient than filters of not crimped fibers, so that they can be pressed together for saving space during transport and storage.

The product obtained by the method according to the invention can besides being used as filter, also be used as a dust remover. By rubbing a piece of the filter material over a surface, e.g. the surface of a record, the surface becomes completely free of dust while the coherence of the fibers as result of their crimp avoids that loose fibers of the filter material remain on the surface.

The invention will now be described with the aid of a drawing.

FIG. 1 shows schematically the method according to the invention;

FIG. 2 shows the penetration as function of the loading with dust of a crimped filter according to the invention and of a comparable not-crimped filter.

Each of the extruders 31 and 32 supply a component of the high molecular weight, polymeric substance, each of them differing in molecular weight, to a common nozzle 33 with the strip-like extrusion mouth 34. The thus obtained foil 1, in which both components are present in a laminate-shaped non-homogeneous distribution, is after passing the rollers 3 and 4 subjected to a first drawing between the roller pair 5 and 6 and the roller pair 9 and 10 rotating at a higher speed, in which it is drawn over an edge 7 of a block 8 provided with a schematically indicated heater 15. Between the roller pair 9 and 10 and the roller pair 13 and 14 rotating at a still higher speed the foil 1 is subjected to a second drawing while it is advanced over a bent plate 12, provided with a schematically indicated heater 16. At the same time, the foil 1 is electrically charged by the spray device 18, comprising corona wires 25 being connected to a not shown high-tension source and of which the plate 12 forms the anti-pole. The splittable electret foil 1 obtained in this manner subsequently is advanced via the support roll 20 over the needle roll 29, which fibrillates the foil 1 to a fibrillated fiber band 35. Subsequently, the latter is widened by the spreading device 36 to a net-like fiber fleece 37 and wound on to the roll 38.

When in this way a fiber mat of the desired thickness is wound, it is taken from the roll 38 by cutting it in the direction of the axis of the roll or by pushing it from the roll 38 without cutting. The fibers of which the fiber mat exists now are not held anymore in straightened shape and crimp spontaneously as result of the different measure of relaxation-crimp in both components of the high-molecular substance of which they are made. The fibers mesh with each other and form a filter mat with a homogeneous and firm structure, which is further still improved by a heat treatment of about 15 minutes in an oven not shown in the drawing, of which the temperature is kept at about 70° C.

FIG. 2 shows a diagram in which on the ordinate penetration, defined as the ratio of the dust concentration behind the filter to that before the filter is shown in percentages, and on the abscis the dust loading of the filter in g/m2. The solid line shows the result for a crimped electret filter obtained according to the invention and the dashed line for a comparable not crimped electret filter.

The diagram shows, that the penetration of perviousness for the not catched dust of the electret filter of crimped fibers with increasing dust loading is subsequently lower than that of the filter of not crimped fibers, so in practice the crimped filter has a much longer life-time than the not-crimped filter.

EXAMPLE

According to the method described with the aid of FIG. 1 a laminate having a thickness of 50/μm and a width of 6 cm consisting of polypropylene with a melt flow index of 1.5 and polypropylene with a melt flow index of 8 is drawn with an initial speed of 13 m/minute over block 8, having a temperature of about 100° C., in a draw ratio of 1:6 and subsequently over the plate 12 having a temperature of about 150° C. in a draw ratio of 1:1.5. The corona wires 25 are present 5 mm above the foil and have a tension of -10 kV with regard to the plate 12. The foil is fibrillated with a needle roller with 60 rows of which the needles are positioned at a mutual distance of 0.5 mm. The obtained split fiber band is spread to a width of 90 cm and is wound in 170 layers to a fiber mat with a thickness of 3 mm. The fiber mat is taken from the roll and is placed during 15 minutes in an oven at 70° C. The obtained filter cloth appeared to have a density of 250 g/m2.

In FIG. 2 the solid line shows the filter features of this cloth. The filter of not crimped fibers compared herewith, of which filter the dashed line shows the features, is obtained by in the same manner drawing, fibrillating and winding a foil with the same dimensions but comprising exclusively polypropylene with a melt flow index of 1.5 and winding it to a filter bat with also a density of 250 g/m2.

During testing both filters showed practically no difference in flow resistance and the resistance increased for both filters only in neglectable measure.

Claims (6)

We claim:
1. A method for manufacturing a filter of electrically charged electret fiber material, consisting of a high-molecular weight, non-polar polymeric substance, comprising the steps of: continuously supplying a foil of said substance, drawing, charging and fibrillating of the foil and the processing of the thus obtained filter material into a filter, selecting the foil and/or the type of drawing to manufacture spontaneously crimpable fiber material, winding said material in uncrimped condition to a fibrous package and subsequently effecting crimping to interlock the fibers of said fibrous package.
2. A method according to claim 1, further comprising the step of heat treating the filter.
3. A method according to claim 1, wherein a foil is used in which at least two substances with different drawing or crimping characteristics are incorporated in a non-homogeneous mixture.
4. A method according to claim 3, wherein a foil is used being a laminate of said at least two substances.
5. A method according to claim 1, further comprising the step of deforming the foil during or after the step of drawing.
6. A filter produced by the method according to claim 1. .Iadd. 7. An electret fibrous web comprising fibers fibrillated from a film of a high-molecular-weight nonpolar substance and which contain electric charges embedded therein so as to enhance filtration properties of the web, said fibers being crimped after fibrillation and intermeshed with one another, said fibrous web being capable of being loaded with high amounts of dust while still maintaining high filtration efficiency. .Iaddend..Iadd. 8. An electret fibrous web of claim 7 in which said fibers comprise polypropylene. .Iaddend..Iadd. 9. An electret fibrous web of claim 7 in which said fibers are fibrillated from a film that comprises a laminate of at least two different high-molecular-weight nonpolar substances. .Iaddend..Iadd. 10. An electret fibrous web of claim 9 in which both of said different substances comprise polypropylene. .Iaddend.
US06328027 1976-12-23 1981-12-07 Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method Expired - Lifetime USRE31285E (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
NL7614376A NL181632C (en) 1976-12-23 1976-12-23 Electreetfilter and method for manufacturing the same.
NL7614376 1976-12-23

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US05862768 Reissue US4178157A (en) 1976-12-23 1977-12-21 Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method

Publications (1)

Publication Number Publication Date
USRE31285E true USRE31285E (en) 1983-06-21

Family

ID=19827446

Family Applications (2)

Application Number Title Priority Date Filing Date
US05862768 Expired - Lifetime US4178157A (en) 1976-12-23 1977-12-21 Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method
US06328027 Expired - Lifetime USRE31285E (en) 1976-12-23 1981-12-07 Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US05862768 Expired - Lifetime US4178157A (en) 1976-12-23 1977-12-21 Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method

Country Status (10)

Country Link
US (2) US4178157A (en)
JP (1) JPS5714467B2 (en)
BE (1) BE862156A (en)
CA (1) CA1105217A (en)
DE (1) DE2756826C2 (en)
DK (1) DK152016C (en)
FR (1) FR2374939B1 (en)
GB (1) GB1572199A (en)
LU (1) LU78749A1 (en)
NL (1) NL181632C (en)

Cited By (92)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE32171E (en) 1974-03-25 1986-06-03 Minnesota Mining And Manufacturing Company Method for the manufacture of an electret fibrous filter
US5230800A (en) * 1992-02-20 1993-07-27 Minnesota Mining And Manufacturing Company Scrim inserted electrostatic fibrous filter web
US5266369A (en) * 1988-09-21 1993-11-30 Toray Industries, Inc. Packaging material made of electret material and packaging method
US5268009A (en) * 1992-12-22 1993-12-07 Teledyne Industries, Inc. Portable air filter system
US5304227A (en) * 1990-11-30 1994-04-19 Mitsui Petrochemical Industries, Ltd. Electret filters
US5374458A (en) * 1992-03-13 1994-12-20 Minnesota Mining And Manufacturing Company Molded, multiple-layer face mask
US5411576A (en) * 1993-03-26 1995-05-02 Minnesota Mining And Manufacturing Company Oily mist resistant electret filter media and method for filtering
US5436054A (en) * 1993-10-20 1995-07-25 Toyo Boseki Kabushiki Kaisha Electret Filter
US5496507A (en) * 1993-08-17 1996-03-05 Minnesota Mining And Manufacturing Company Method of charging electret filter media
US5499917A (en) * 1993-06-29 1996-03-19 Minnesota Mining And Manufacturing Company Dental isolation dam
US5641555A (en) * 1993-08-17 1997-06-24 Minnesota Mining And Manufacturing Company Cup-shaped filtration mask having an undulated surface
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
US5724677A (en) * 1996-03-08 1998-03-10 Minnesota Mining And Manufacturing Company Multi-part headband and respirator mask assembly and process for making same
US5792242A (en) * 1996-02-26 1998-08-11 Minnesota Mining And Manufacturing Co. Electrostatic fibrous filter web
US5807366A (en) * 1994-12-08 1998-09-15 Milani; John Absorbent article having a particle size gradient
US5814570A (en) * 1994-06-27 1998-09-29 Kimberly-Clark Worldwide, Inc. Nonwoven barrier and method of making the same
US5821178A (en) * 1994-12-30 1998-10-13 Kimberly-Clark Worldwide, Inc. Nonwoven laminate barrier material
US5830810A (en) * 1995-07-19 1998-11-03 Kimberly-Clark Worldwide, Inc. Nonwoven barrier and method of making the same
US5834384A (en) * 1995-11-28 1998-11-10 Kimberly-Clark Worldwide, Inc. Nonwoven webs with one or more surface treatments
US5998308A (en) 1994-02-22 1999-12-07 Kimberly-Clark Worldwide, Inc. Nonwoven barrier and method of making the same
US6174964B1 (en) 1999-09-24 2001-01-16 3M Innovative Properties Company Fluorochemical oligomer and use thereof
US6213122B1 (en) 1997-10-01 2001-04-10 3M Innovative Properties Company Electret fibers and filter webs having a low level of extractable hydrocarbons
US6234171B1 (en) 1997-12-01 2001-05-22 3M Innovative Properties Company Molded respirator containing sorbent particles
US6273938B1 (en) 1999-08-13 2001-08-14 3M Innovative Properties Company Channel flow filter
US6279570B1 (en) 1999-03-02 2001-08-28 3M Innovative Properties Company Filter support, assembly and system
US6280824B1 (en) 1999-01-29 2001-08-28 3M Innovative Properties Company Contoured layer channel flow filtration media
US6288157B1 (en) 1999-05-11 2001-09-11 3M Innovative Properties Company Alkylated fluorochemical oligomers and use thereof
US6365088B1 (en) 1998-06-26 2002-04-02 Kimberly-Clark Worldwide, Inc. Electret treatment of high loft and low density nonwoven webs
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
US6391948B1 (en) 1999-12-14 2002-05-21 3M Innovative Properties Company Triazine compounds and use thereof
US6391807B1 (en) 1999-09-24 2002-05-21 3M Innovative Properties Company Polymer composition containing a fluorochemical oligomer
US6394090B1 (en) 1999-02-17 2002-05-28 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US6398847B1 (en) * 1998-07-02 2002-06-04 3M Innovative Properties Company Method of removing contaminants from an aerosol using a new electret article
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
US6419729B1 (en) 2000-04-17 2002-07-16 3M Innovative Properties Company Filter assemblies with adhesive attachment systems
US6420024B1 (en) 2000-12-21 2002-07-16 3M Innovative Properties Company Charged microfibers, microfibrillated articles and use thereof
US6432347B1 (en) 1999-02-05 2002-08-13 3M Innovative Properties Company Process of making a microfibrillated article
US6454839B1 (en) 1999-10-19 2002-09-24 3M Innovative Properties Company Electrofiltration apparatus
US6454986B1 (en) 1999-10-08 2002-09-24 3M Innovative Properties Company Method of making a fibrous electret web using a nonaqueous polar liquid
EP1258267A2 (en) 1995-03-09 2002-11-20 Minnesota Mining And Manufacturing Company Flat-folded personal respiratory protection devices and process for preparing same
US6484722B2 (en) 1995-09-11 2002-11-26 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US6525127B1 (en) 1999-05-11 2003-02-25 3M Innovative Properties Company Alkylated fluorochemical oligomers and use thereof in the treatment of fibrous substrates
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
US6537932B1 (en) 1997-10-31 2003-03-25 Kimberly-Clark Worldwide, Inc. Sterilization wrap, applications therefor, and method of sterilizing
US6589317B2 (en) 2001-08-10 2003-07-08 3M Innovative Properties Company Structured surface filtration media array
US6630231B2 (en) 1999-02-05 2003-10-07 3M Innovative Properties Company Composite articles reinforced with highly oriented microfibers
US6680114B2 (en) 2001-05-15 2004-01-20 3M Innovative Properties Company Fibrous films and articles from microlayer substrates
US20040024262A1 (en) * 1999-05-11 2004-02-05 Jariwala Chetan P Alkylated fluorochemical oligomers and use thereof in the treatment of fibrous substrates
US20040112213A1 (en) * 2001-04-07 2004-06-17 Klaus Dominiak Combination filter for filtering fluids
US6758884B2 (en) 2002-08-07 2004-07-06 3M Innovative Properties Company Air filtration system using point ionization sources
US6783574B1 (en) 1993-08-17 2004-08-31 Minnesota Mining And Manufacturing Company Electret filter media and filtering masks that contain electret filter media
US6874499B2 (en) 2002-09-23 2005-04-05 3M Innovative Properties Company Filter element that has a thermo-formed housing around filter material
US20050160907A1 (en) * 2004-01-22 2005-07-28 3M Innovative Properties Company Air filtration system using point ionization sources
US6923182B2 (en) 2002-07-18 2005-08-02 3M Innovative Properties Company Crush resistant filtering face mask
US20060196157A1 (en) * 2005-03-03 2006-09-07 Greer Paul A Conformal filter cartridges and methods
WO2007037903A2 (en) 2005-09-16 2007-04-05 3M Innovative Properties Company Abrasive article with integrated filter and method of making same
US20070287366A1 (en) * 2006-06-13 2007-12-13 3M Innovative Properties Company Abrasive article and methods of making and using the same
US20080229672A1 (en) * 2007-03-20 2008-09-25 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
US20080276805A1 (en) * 2005-04-22 2008-11-13 Marcus Lotgerink-Bruinenberg Vehicle Passenger Compartment Air Filter Devices
US20090293279A1 (en) * 2008-06-02 2009-12-03 3M Innovative Properties Company Method of making electret articles based on zeta potential
WO2010114826A1 (en) 2009-04-03 2010-10-07 3M Innovative Properties Company Remote fluorination of fibrous filter webs
US20110041471A1 (en) * 2007-12-06 2011-02-24 Sebastian John M Electret webs with charge-enhancing additives
EP2298096A2 (en) 2009-09-18 2011-03-23 3M Innovative Properties Co. Filtering face respirator having grasping feature indicator
EP2298419A1 (en) 2009-09-18 2011-03-23 3M Innovative Properties Co. Flat-fold filtering face-piece respirator having structural weld pattern
EP2298095A2 (en) 2009-09-18 2011-03-23 3M Innovative Properties Co. Horizontal flat-fold filtering face-piece respirator having indicia of symmetry
EP2314353A1 (en) 2009-10-23 2011-04-27 3M Innovative Properties Company Filtering face-piece respirator having parallel line weld pattern in mask body
US20110137082A1 (en) * 2008-06-02 2011-06-09 Li Fuming B Charge-enhancing additives for electrets
US20110154987A1 (en) * 2008-06-02 2011-06-30 Li Fuming B Electret webs with charge-enhancing additives
WO2011090586A2 (en) 2009-12-30 2011-07-28 3M Innovative Properties Company Filtering face-piece respirator having an auxetic mesh in the mask body
EP2412407A1 (en) 2010-07-26 2012-02-01 3M Innovative Properties Co. Filtering face-piece respiratory having foam shaping layer
EP2428127A2 (en) 2007-05-03 2012-03-14 3M Innovative Properties Company Maintenance-free respirator that has concave portions on opposing sides of mask top section
WO2012068091A2 (en) 2010-11-19 2012-05-24 3M Innovative Properties Company Filtering face-piece respirator having an overmolded face seal
US8585808B2 (en) 2010-11-08 2013-11-19 3M Innovative Properties Company Zinc oxide containing filter media and methods of forming the same
US8790449B2 (en) 2009-04-03 2014-07-29 3M Innovative Properties Company Electret webs with charge-enhancing additives
WO2014172308A2 (en) 2013-04-19 2014-10-23 3M Innovative Properties Company Electret webs with charge-enhancing additives
WO2015130591A1 (en) 2014-02-27 2015-09-03 3M Innovative Properties Company Respirator having elastic straps having openwork structure
WO2015199972A1 (en) 2014-06-23 2015-12-30 3M Innovative Properties Company Electret webs with charge-enhancing additives
WO2016028553A1 (en) 2014-08-18 2016-02-25 3M Innovative Properties Company Respirator including polymeric netting and method of forming same
US9284669B2 (en) 2009-04-03 2016-03-15 3M Innovative Properties Company Processing aids for olefinic webs, including electret webs
WO2016069342A1 (en) 2014-10-31 2016-05-06 3M Innovative Properties Company Respirator having corrugated filtering structure
WO2016090072A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Flat-fold respirator
WO2016089940A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator valve
WO2016090067A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator tab
WO2016090082A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator nosepiece
WO2016089937A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator headband
US20160250649A1 (en) * 2013-10-15 2016-09-01 Yupo Corporation Filter
WO2016182989A1 (en) 2015-05-12 2016-11-17 3M Innovative Properties Company Respirator tab
US9539532B2 (en) 2010-01-18 2017-01-10 3M Innovative Properties Company Air filter with sorbent particles
WO2017066284A1 (en) 2015-10-12 2017-04-20 3M Innovative Properties Company Filtering face-piece respirator including functional material and method of forming same
WO2017100045A1 (en) 2015-12-11 2017-06-15 3M Innovative Properties Company Fluorinated piperazine sulfonamides
US9815068B2 (en) 2012-12-28 2017-11-14 3M Innovative Properties Company Electret webs with charge-enhancing additives

Families Citing this family (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2927238C2 (en) * 1978-07-07 1987-12-23 Danaklon A/S, Varde, Dk
JPH0139889B2 (en) * 1979-02-26 1989-08-24 Sanso Jushi Kogyo Kk
US4308223A (en) * 1980-03-24 1981-12-29 Albany International Corp. Method for producing electret fibers for enhancement of submicron aerosol filtration
FR2480807B1 (en) * 1980-04-18 1983-11-10 Seplast Sa
US4376642A (en) * 1980-08-18 1983-03-15 Biotech Electronics Ltd. Portable air cleaner unit
US4456648A (en) * 1983-09-09 1984-06-26 Minnesota Mining And Manufacturing Company Particulate-modified electret fibers
DE3509857C2 (en) * 1984-03-19 1994-04-28 Toyo Boseki Elektretisiertes dust filter and its production
DE3908498C2 (en) * 1988-03-15 1997-08-21 Maico Elektroapparate Fan
DE3904623A1 (en) * 1989-02-16 1990-08-23 Sandler Helmut Helsa Werke Filter in particular for a vehicle
JP2788976B2 (en) * 1989-04-26 1998-08-20 ジャパンゴアテック株式会社 Filter material
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
DE4241517C2 (en) * 1992-12-10 1995-09-21 Freudenberg Carl Fa Method and apparatus for producing a spunbonded nonwoven fabric
EP0646416A1 (en) * 1993-10-04 1995-04-05 Trion Inc. Bipolar charged filter and method of using 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
WO1996037276A1 (en) * 1995-05-25 1996-11-28 Kimberly-Clark Worldwide, Inc. Filter matrix
US5898981A (en) * 1996-04-30 1999-05-04 Minnesota Mining & Manufacturing Company Synthetic filter media and method for manufacturing same
US6211100B1 (en) * 1996-04-30 2001-04-03 Minnesota Mining And Manufacturing Company Synthetic filter media
CN1077814C (en) * 1996-12-11 2002-01-16 尼卡斯特有限公司 Device for manufacture of composite filtering material and method of its manufacture
DE69935264D1 (en) * 1999-06-07 2007-04-05 Nicast Ltd Filter material and apparatus and methods for making
US5871836A (en) * 1997-08-27 1999-02-16 Airflo Europe N.V. Composite pleated fibrous structures containing split film fibers
DE60100985D1 (en) * 2001-03-02 2003-11-20 Airflo Europ N V A multi-layer filter and process for its preparation
US6969484B2 (en) 2001-06-18 2005-11-29 Toray Industries, Inc. Manufacturing method and device for electret processed product
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
US7235122B2 (en) * 2004-11-08 2007-06-26 E. I. Du Pont De Nemours And Company Filtration media for filtering particulate material from gas streams
US20060137317A1 (en) * 2004-12-28 2006-06-29 Bryner Michael A Filtration media for filtering particulate material from gas streams
US9134471B2 (en) 2006-06-28 2015-09-15 3M Innovative Properties Company Oriented polymeric articles and method
US7981177B2 (en) * 2007-04-18 2011-07-19 Transweb, Llc Filtration media having a slit-film layer
US8282712B2 (en) 2008-04-07 2012-10-09 E I Du Pont De Nemours And Company Air filtration medium with improved dust loading capacity and improved resistance to high humidity environment
US20110091717A1 (en) * 2008-06-30 2011-04-21 Weiss Douglas E Method for in situ formation of metal nanoclusters within a porous substrate field
US20110290119A1 (en) 2009-02-20 2011-12-01 3M Innovative Properties Company Antimicrobial electret web
DE102009037740A1 (en) * 2009-08-17 2011-02-24 Oerlikon Textile Gmbh & Co. Kg Method and apparatus for producing a yarn grass
WO2015061257A9 (en) 2013-10-21 2015-09-03 E. I. Du Pont De Nemours And Company Electret nanofibrous web as air filtration media

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3378997A (en) * 1965-09-28 1968-04-23 Matsui Mitsuo Method and apparatus for manufacturing bulky crimped yarn from synthetic resin films
US3550517A (en) * 1968-06-07 1970-12-29 Bell & Howell Co Triangulation rangefinding mechanism with locking device
US3578739A (en) * 1969-05-13 1971-05-18 Du Pont Apparatus for applying electrostatic charge to fibrous structure
US3608024A (en) * 1967-02-09 1971-09-21 Polymer Processing Res Inst Method for producing crimped conjugated split fiber
US3966597A (en) * 1970-07-28 1976-06-29 Teijin Limited Oil or organic solvent-absorbent
US3998916A (en) * 1974-03-25 1976-12-21 N.V. Verto Method for the manufacture of an electret fibrous filter

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3336174A (en) * 1965-04-06 1967-08-15 Eastman Kodak Co Method of making a fibrous filter product
GB1094933A (en) * 1965-04-20 1967-12-13 Ici Ltd Self-crimping filaments
GB1151076A (en) * 1966-01-31 1969-05-07 Chori Co Ltd Method and Apparatus for Manufacturing Bulky Crimped Yarn from Synthetic Resin Films.
GB1167631A (en) * 1967-03-20 1969-10-15 Shell Int Research Process and apparatus for the fibrillation of thermoplastic films
BE789078A (en) * 1971-09-22 1973-03-21 Tno A method and apparatus for providing plastic film

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3378997A (en) * 1965-09-28 1968-04-23 Matsui Mitsuo Method and apparatus for manufacturing bulky crimped yarn from synthetic resin films
US3608024A (en) * 1967-02-09 1971-09-21 Polymer Processing Res Inst Method for producing crimped conjugated split fiber
US3550517A (en) * 1968-06-07 1970-12-29 Bell & Howell Co Triangulation rangefinding mechanism with locking device
US3578739A (en) * 1969-05-13 1971-05-18 Du Pont Apparatus for applying electrostatic charge to fibrous structure
US3966597A (en) * 1970-07-28 1976-06-29 Teijin Limited Oil or organic solvent-absorbent
US3998916A (en) * 1974-03-25 1976-12-21 N.V. Verto Method for the manufacture of an electret fibrous filter
USRE30782E (en) 1974-03-25 1981-10-27 Minnesota Mining And Manufacturing Company Method for the manufacture of an electret fibrous filter

Cited By (140)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE32171E (en) 1974-03-25 1986-06-03 Minnesota Mining And Manufacturing Company Method for the manufacture of an electret fibrous filter
US5266369A (en) * 1988-09-21 1993-11-30 Toray Industries, Inc. Packaging material made of electret material and packaging method
US5304227A (en) * 1990-11-30 1994-04-19 Mitsui Petrochemical Industries, Ltd. Electret filters
US5230800A (en) * 1992-02-20 1993-07-27 Minnesota Mining And Manufacturing Company Scrim inserted electrostatic fibrous filter web
US5374458A (en) * 1992-03-13 1994-12-20 Minnesota Mining And Manufacturing Company Molded, multiple-layer face mask
US5268009A (en) * 1992-12-22 1993-12-07 Teledyne Industries, Inc. Portable air filter system
US5472481A (en) * 1993-03-26 1995-12-05 Minnesota Mining And Manufacturing Company Oily mist resistant electret filter media
US5411576A (en) * 1993-03-26 1995-05-02 Minnesota Mining And Manufacturing Company Oily mist resistant electret filter media and method for filtering
US5499917A (en) * 1993-06-29 1996-03-19 Minnesota Mining And Manufacturing Company Dental isolation dam
US5496507A (en) * 1993-08-17 1996-03-05 Minnesota Mining And Manufacturing Company Method of charging electret filter media
US6783574B1 (en) 1993-08-17 2004-08-31 Minnesota Mining And Manufacturing Company Electret filter media and filtering masks that contain electret filter media
US5641555A (en) * 1993-08-17 1997-06-24 Minnesota Mining And Manufacturing Company Cup-shaped filtration mask having an undulated surface
US5643507A (en) * 1993-08-17 1997-07-01 Minnesota Mining And Manufacturing Company Filter media having an undulated surface
US5436054A (en) * 1993-10-20 1995-07-25 Toyo Boseki Kabushiki Kaisha Electret Filter
US5998308A (en) 1994-02-22 1999-12-07 Kimberly-Clark Worldwide, Inc. Nonwoven barrier and method of making the same
US5814570A (en) * 1994-06-27 1998-09-29 Kimberly-Clark Worldwide, Inc. Nonwoven barrier and method of making the same
US5807366A (en) * 1994-12-08 1998-09-15 Milani; John Absorbent article having a particle size gradient
US5916204A (en) 1994-12-08 1999-06-29 Kimberly-Clark Worldwide, Inc. Method of forming a particle size gradient in an absorbent article
US5821178A (en) * 1994-12-30 1998-10-13 Kimberly-Clark Worldwide, Inc. Nonwoven laminate barrier material
US6886563B2 (en) 1995-03-09 2005-05-03 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
EP1258267A2 (en) 1995-03-09 2002-11-20 Minnesota Mining And Manufacturing Company Flat-folded personal respiratory protection devices and process for preparing same
US20050139218A1 (en) * 1995-03-09 2005-06-30 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US7069930B2 (en) 1995-03-09 2006-07-04 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US20060180152A1 (en) * 1995-03-09 2006-08-17 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
EP2229983A1 (en) 1995-03-09 2010-09-22 3M Innovative Properties Company Flat-folded personal respiratory protection devices
US8146594B2 (en) 1995-03-09 2012-04-03 3M Innovative Properties Company Flat-folded personal respiratory protection devices
US20040237964A1 (en) * 1995-03-09 2004-12-02 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US8375950B2 (en) 1995-03-09 2013-02-19 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US5830810A (en) * 1995-07-19 1998-11-03 Kimberly-Clark Worldwide, Inc. Nonwoven barrier and method of making the same
US6722366B2 (en) 1995-09-11 2004-04-20 3M Innovative Properties Company Method of making a flat-folded personal respiratory protection device
US6715489B2 (en) 1995-09-11 2004-04-06 3M Innovative Properties Company Processes for preparing flat-folded personal respiratory protection devices
US6484722B2 (en) 1995-09-11 2002-11-26 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US6536434B1 (en) 1995-09-11 2003-03-25 3M Innovative Properties Company Flat-folded personal respiratory protection devices and processes for preparing same
US5834384A (en) * 1995-11-28 1998-11-10 Kimberly-Clark Worldwide, Inc. Nonwoven webs with one or more surface treatments
US5792242A (en) * 1996-02-26 1998-08-11 Minnesota Mining And Manufacturing Co. Electrostatic fibrous filter web
US5800769A (en) * 1996-02-26 1998-09-01 Haskett; Thomas E. Method for forming an electrostatic fibrous filter web
US5724677A (en) * 1996-03-08 1998-03-10 Minnesota Mining And Manufacturing Company Multi-part headband and respirator mask assembly and process for making same
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
US6776951B2 (en) 1997-10-01 2004-08-17 3M Innovative Properties Company Method of making electret fibers
US6319452B1 (en) 1997-10-01 2001-11-20 3M Innovative Properties Company Method of making electret fibers that have low level of extractable hydrocarbon material
US6213122B1 (en) 1997-10-01 2001-04-10 3M Innovative Properties Company Electret fibers and filter webs having a low level of extractable hydrocarbons
US6237595B1 (en) 1997-10-01 2001-05-29 3M Innovative Properties Company Predicting electret performance by measuring level of extractable hydrocarbons
US6537932B1 (en) 1997-10-31 2003-03-25 Kimberly-Clark Worldwide, Inc. Sterilization wrap, applications therefor, and method of sterilizing
US6234171B1 (en) 1997-12-01 2001-05-22 3M Innovative Properties Company Molded respirator containing sorbent particles
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
US6365088B1 (en) 1998-06-26 2002-04-02 Kimberly-Clark Worldwide, Inc. Electret treatment of high loft and low density nonwoven webs
US6660210B2 (en) 1998-07-02 2003-12-09 3M Innovative Properties Company Method of making fluorinated electrets
US6432175B1 (en) * 1998-07-02 2002-08-13 3M Innovative Properties Company Fluorinated electret
US20040207125A1 (en) * 1998-07-02 2004-10-21 3M Innovative Properties Company Method of making a respirator that has a fluorinated electret
US6562112B2 (en) 1998-07-02 2003-05-13 3M Innovative Properties Company Fluorinated electret
US6953544B2 (en) 1998-07-02 2005-10-11 3M Innovative Properties Company Method of making a respirator that has a fluorinated electret
US6808551B2 (en) 1998-07-02 2004-10-26 3M Innovative Properties Company Method of using fluorinated electrets
US6398847B1 (en) * 1998-07-02 2002-06-04 3M Innovative Properties Company Method of removing contaminants from an aerosol using a new electret article
US6752889B2 (en) 1999-01-29 2004-06-22 3M Innovative Properties Company Contoured layer channel flow filtration media
US6280824B1 (en) 1999-01-29 2001-08-28 3M Innovative Properties Company Contoured layer channel flow filtration media
US6432347B1 (en) 1999-02-05 2002-08-13 3M Innovative Properties Company Process of making a microfibrillated article
US7014803B2 (en) 1999-02-05 2006-03-21 3M Innovative Properties Company Composite articles reinforced with highly oriented microfibers
US6432532B2 (en) 1999-02-05 2002-08-13 3M Innovative Properties Company Microfibers and method of making
US6630231B2 (en) 1999-02-05 2003-10-07 3M Innovative Properties Company Composite articles reinforced with highly oriented microfibers
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
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
US20040024262A1 (en) * 1999-05-11 2004-02-05 Jariwala Chetan P Alkylated fluorochemical oligomers and use thereof in the treatment of fibrous substrates
US6273938B1 (en) 1999-08-13 2001-08-14 3M Innovative Properties Company Channel flow filter
US6284843B1 (en) 1999-09-24 2001-09-04 3M Innovative Properties Company Fluorochemical oligomer and use thereof
US6391807B1 (en) 1999-09-24 2002-05-21 3M Innovative Properties Company Polymer composition containing a fluorochemical oligomer
US6174964B1 (en) 1999-09-24 2001-01-16 3M Innovative Properties Company Fluorochemical oligomer and use thereof
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
US6454986B1 (en) 1999-10-08 2002-09-24 3M Innovative Properties Company Method of making a fibrous electret web using a nonaqueous polar liquid
US6824718B2 (en) 1999-10-08 2004-11-30 3M Innovative Properties Company Process of making a fibrous electret web
US20020110610A1 (en) * 1999-10-08 2002-08-15 3M Innovative Properties Company Apparatus for making a nonwoven fibrous electret web from free-fiber and 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
US20020190434A1 (en) * 1999-10-08 2002-12-19 3M Innovative Properties Company Method and apparatus for making a fibrous electret web using a wetting liquid and an aqueous polar liquid
US6471746B2 (en) 1999-10-19 2002-10-29 3M Innovative Properties Company Electrofiltration process
US6454839B1 (en) 1999-10-19 2002-09-24 3M Innovative Properties Company Electrofiltration apparatus
US6391948B1 (en) 1999-12-14 2002-05-21 3M Innovative Properties Company Triazine compounds and use thereof
US6419729B1 (en) 2000-04-17 2002-07-16 3M Innovative Properties Company Filter assemblies with adhesive attachment systems
US20020172816A1 (en) * 2000-12-21 2002-11-21 3M Innovative Properties Company Charged microfibers, microfibrillated articles and use thereof
US6420024B1 (en) 2000-12-21 2002-07-16 3M Innovative Properties Company Charged microfibers, microfibrillated articles and use thereof
US6849329B2 (en) 2000-12-21 2005-02-01 3M Innovative Properties Company Charged microfibers, microfibrillated articles and use thereof
US6986804B2 (en) 2001-04-07 2006-01-17 3M Innovative Properties Company Combination filter for filtering fluids
US20040112213A1 (en) * 2001-04-07 2004-06-17 Klaus Dominiak Combination filter for filtering fluids
US6680114B2 (en) 2001-05-15 2004-01-20 3M Innovative Properties Company Fibrous films and articles from microlayer substrates
US6589317B2 (en) 2001-08-10 2003-07-08 3M Innovative Properties Company Structured surface filtration media array
US6923182B2 (en) 2002-07-18 2005-08-02 3M Innovative Properties Company Crush resistant filtering face mask
US6758884B2 (en) 2002-08-07 2004-07-06 3M Innovative Properties Company Air filtration system using point ionization sources
US20050161045A1 (en) * 2002-09-23 2005-07-28 3M Innovative Properties Company Method of making a filter cartridge that uses thermoforming step
US6874499B2 (en) 2002-09-23 2005-04-05 3M Innovative Properties Company Filter element that has a thermo-formed housing around filter material
US7497217B2 (en) 2002-09-23 2009-03-03 3M Innovative Properties Company Method of making a filter cartridge using a thermoforming step
US7141098B2 (en) 2004-01-22 2006-11-28 3M Innovative Properties Company Air filtration system using point ionization sources
US20050160907A1 (en) * 2004-01-22 2005-07-28 3M Innovative Properties Company Air filtration system using point ionization sources
US20060196157A1 (en) * 2005-03-03 2006-09-07 Greer Paul A Conformal filter cartridges and methods
US7419526B2 (en) 2005-03-03 2008-09-02 3M Innovative Properties Company Conformal filter cartridges and methods
US20080276805A1 (en) * 2005-04-22 2008-11-13 Marcus Lotgerink-Bruinenberg Vehicle Passenger Compartment Air Filter Devices
WO2007037903A2 (en) 2005-09-16 2007-04-05 3M Innovative Properties Company Abrasive article with integrated filter and method of making same
US20070287366A1 (en) * 2006-06-13 2007-12-13 3M Innovative Properties Company Abrasive article and methods of making and using the same
US7338355B2 (en) 2006-06-13 2008-03-04 3M Innovative Properties Company Abrasive article and methods of making and using the same
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
US20080229672A1 (en) * 2007-03-20 2008-09-25 3M Innovative Properties Company Abrasive article and method of making and using the same
EP2428127A2 (en) 2007-05-03 2012-03-14 3M Innovative Properties Company Maintenance-free respirator that has concave portions on opposing sides of mask top section
US8529671B2 (en) 2007-12-06 2013-09-10 3M Innovative Properties Comany Electret webs with charge-enhancing additives
US20110041471A1 (en) * 2007-12-06 2011-02-24 Sebastian John M Electret webs with charge-enhancing additives
US8613795B2 (en) 2008-06-02 2013-12-24 3M Innovative Properties Company Electret webs with charge-enhancing additives
US20090293279A1 (en) * 2008-06-02 2009-12-03 3M Innovative Properties Company Method of making electret articles based on zeta potential
US20110154987A1 (en) * 2008-06-02 2011-06-30 Li Fuming B Electret webs with charge-enhancing additives
US20110137082A1 (en) * 2008-06-02 2011-06-09 Li Fuming B Charge-enhancing additives for electrets
US7765698B2 (en) 2008-06-02 2010-08-03 3M Innovative Properties Company Method of making electret articles based on zeta potential
US20100252047A1 (en) * 2009-04-03 2010-10-07 Kirk Seth M Remote fluorination of fibrous filter webs
US8790449B2 (en) 2009-04-03 2014-07-29 3M Innovative Properties Company Electret webs with charge-enhancing additives
WO2010114826A1 (en) 2009-04-03 2010-10-07 3M Innovative Properties Company Remote fluorination of fibrous filter webs
US9284669B2 (en) 2009-04-03 2016-03-15 3M Innovative Properties Company Processing aids for olefinic webs, including electret webs
EP2298419A1 (en) 2009-09-18 2011-03-23 3M Innovative Properties Co. Flat-fold filtering face-piece respirator having structural weld pattern
EP2298096A2 (en) 2009-09-18 2011-03-23 3M Innovative Properties Co. Filtering face respirator having grasping feature indicator
US9826786B2 (en) 2009-09-18 2017-11-28 3M Innovative Properties Company Horizontal flat-fold filtering face-piece respirator having indicia of symmetry
EP2298095A2 (en) 2009-09-18 2011-03-23 3M Innovative Properties Co. Horizontal flat-fold filtering face-piece respirator having indicia of symmetry
EP2314353A1 (en) 2009-10-23 2011-04-27 3M Innovative Properties Company Filtering face-piece respirator having parallel line weld pattern in mask body
WO2011090586A2 (en) 2009-12-30 2011-07-28 3M Innovative Properties Company Filtering face-piece respirator having an auxetic mesh in the mask body
US9539532B2 (en) 2010-01-18 2017-01-10 3M Innovative Properties Company Air filter with sorbent particles
EP2412407A1 (en) 2010-07-26 2012-02-01 3M Innovative Properties Co. Filtering face-piece respiratory having foam shaping layer
US8585808B2 (en) 2010-11-08 2013-11-19 3M Innovative Properties Company Zinc oxide containing filter media and methods of forming the same
US8753434B2 (en) 2010-11-08 2014-06-17 3M Innovative Properties Company Zinc oxide containing filter media and methods of forming the same
WO2012068091A2 (en) 2010-11-19 2012-05-24 3M Innovative Properties Company Filtering face-piece respirator having an overmolded face seal
US9815068B2 (en) 2012-12-28 2017-11-14 3M Innovative Properties Company Electret webs with charge-enhancing additives
US9815067B2 (en) 2013-04-19 2017-11-14 3M Innovative Properties Company Electret webs with charge-enhancing additives
WO2014172308A2 (en) 2013-04-19 2014-10-23 3M Innovative Properties Company Electret webs with charge-enhancing additives
US20160250649A1 (en) * 2013-10-15 2016-09-01 Yupo Corporation Filter
WO2015130591A1 (en) 2014-02-27 2015-09-03 3M Innovative Properties Company Respirator having elastic straps having openwork structure
WO2015199972A1 (en) 2014-06-23 2015-12-30 3M Innovative Properties Company Electret webs with charge-enhancing additives
WO2016028553A1 (en) 2014-08-18 2016-02-25 3M Innovative Properties Company Respirator including polymeric netting and method of forming same
WO2016069342A1 (en) 2014-10-31 2016-05-06 3M Innovative Properties Company Respirator having corrugated filtering structure
WO2016090082A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator nosepiece
WO2016089940A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator valve
WO2016090072A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Flat-fold respirator
WO2016090067A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator tab
WO2016089937A1 (en) 2014-12-04 2016-06-09 3M Innovative Properties Company Respirator headband
WO2016182989A1 (en) 2015-05-12 2016-11-17 3M Innovative Properties Company Respirator tab
WO2017066284A1 (en) 2015-10-12 2017-04-20 3M Innovative Properties Company Filtering face-piece respirator including functional material and method of forming same
WO2017100045A1 (en) 2015-12-11 2017-06-15 3M Innovative Properties Company Fluorinated piperazine sulfonamides

Also Published As

Publication number Publication date Type
DK152016B (en) 1988-01-25 grant
LU78749A1 (en) 1978-04-17 application
JPS5388272A (en) 1978-08-03 application
CA1105217A1 (en) grant
NL181632B (en) 1987-05-04 application
GB1572199A (en) 1980-07-23 application
NL7614376A (en) 1978-06-27 application
JPS5714467B2 (en) 1982-03-24 grant
DK152016C (en) 1988-07-11 grant
BE862156A (en) 1978-06-22 grant
CA1105217A (en) 1981-07-21 grant
DE2756826A1 (en) 1978-07-06 application
FR2374939B1 (en) 1982-11-26 grant
US4178157A (en) 1979-12-11 grant
FR2374939A1 (en) 1978-07-21 application
BE862156A2 (en) grant
DK575777A (en) 1978-06-24 application
NL181632C (en) 1987-10-01 grant
DE2756826C2 (en) 1985-08-22 grant
JP1119903C (en) grant

Similar Documents

Publication Publication Date Title
US3280229A (en) Process and apparatus for producing patterned non-woven fabrics
US3276597A (en) Filter media
US3595738A (en) Helically crimped filamentary materials
US3705070A (en) Nonwoven fabric and process for preparing
US6119691A (en) Electret filter media
US6253431B1 (en) Air opening jet apparatus
US3390039A (en) Method and apparatus for making additive filters
US4973382A (en) Filtration fabric produced by wet laid process
US4795668A (en) Bicomponent fibers and webs made therefrom
US3240657A (en) Non-woven tuberculated foraminous textile fabric
US6200368B1 (en) Combined filter device for filtering out particles and gases
US2476582A (en) Method of making filter units
US3156016A (en) Tow opening
EP0340982A2 (en) Melt-bondable fibers for use in nonwoven web
US3003304A (en) Method of manufacturing non-woven fabrics and yarns
US4961974A (en) Laminated filters
US7094270B2 (en) Composite filter and method of making the same
US5456982A (en) Bicomponent synthesis fibre and process for producing same
US2881770A (en) Fibrous tobacco smoke filters
US3551271A (en) Nonwoven fabrics containing heterofilaments
US3658626A (en) Means for manufacturing staple fiber filter elements
US3003643A (en) Filter media
US6649547B1 (en) Integrated nonwoven laminate material
US5562986A (en) Polytetrafluoroethylene fibers, polytetrafluoroethylene materials and process for preparation of the same
US4064214A (en) Process for making polytetrafluoroethylene yarn