CA2130246C - Polyethylene meltblown fabric with barrier properties - Google Patents
Polyethylene meltblown fabric with barrier properties Download PDFInfo
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- CA2130246C CA2130246C CA002130246A CA2130246A CA2130246C CA 2130246 C CA2130246 C CA 2130246C CA 002130246 A CA002130246 A CA 002130246A CA 2130246 A CA2130246 A CA 2130246A CA 2130246 C CA2130246 C CA 2130246C
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Classifications
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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
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/02—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
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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
- D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
- D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
- D04H1/724—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged forming webs during fibre formation, e.g. flash-spinning
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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
-
- 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
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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
- D04H1/554—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 by radio-frequency heating
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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
- D04H1/559—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 the fibres being within layered webs
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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
- 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
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/02—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
- D04H3/03—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments at random
-
- 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
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
- D04H3/14—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic yarns or filaments produced by welding
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F13/51—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the outer layers
- A61F13/514—Backsheet, i.e. the impermeable cover or layer furthest from the skin
- A61F13/51474—Backsheet, i.e. the impermeable cover or layer furthest from the skin characterised by its structure
- A61F13/51478—Backsheet, i.e. the impermeable cover or layer furthest from the skin characterised by its structure being a laminate, e.g. multi-layered or with several layers
-
- 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
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/903—Microfiber, less than 100 micron diameter
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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
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
- Y10T428/24826—Spot bonds connect components
-
- 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
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
- Y10T428/249978—Voids specified as micro
- Y10T428/24998—Composite has more than two layers
-
- 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
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
- Y10T428/249981—Plural void-containing components
-
- 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]
- Y10T442/659—Including an additional nonwoven fabric
- Y10T442/66—Additional nonwoven fabric is a spun-bonded fabric
Abstract
A nonwoven fabric is provided which has good barrier properties, softness and breathability. A linear low density polyethylene is used in a meltblown layer in this invention to provide barrier properties comparable to polypropylene. The meltblown layer may be used in a multilayer laminate and the other layers may be comprised of bicomponent fibers. The fabric may be used in, for example, diapers, feminine hygiene products, adult incontinence products, wound dressings, bandages, sterilization wraps, surgical gowns and drapes and wipers.
Description
2~3~~~~~
Docket #: 10,994 POLYETHYLENE MELTBLOWN FABRIC WITH BARRIER PROPERTIES
BACKGROUND OF THE INVENTION
This invention relates generally to a nonwoven fabric or web which is formed from meltblown fibers of thermoplastic polyethylene resin, as well as the process of producing such a fabric.
Thermoplastic resins have been extruded to form fibers and webs for a number of years. The most common thermoplastics for this application are polyolefins, particularly polypropylene. Other materials such as polyesters, polyetheresters, polyamides and polyurethanes are also used for this purpose. Each material has its characteristic advantages and disadvantages vis a vis the properties desired in the final product to be made from such fibers.
Nonwoven fabrics are useful for a wide variety of applications such as diapers, feminine hygiene products, incontinence products, towels, medical garments and many others. The nonwoven fabrics used in these applications are often in the form of laminates like spunbond/meltblown/spunbond (SMS) laminates. In SMS
laminates the exterior layers are generally spunbond polypropylene which are usually present for strength, and the interior layer which is generally meltblown polypropylene and is usually present as a barrier layer.
It is desirable that the meltblown barrier fabric layer have good barrier properties yet also be as soft and drapeable as possible. Polypropylene meltblown fabrics, while usually possessing good barrier properties, are not as soft and drapeable as polyethylene fabrics.
Polyethylene meltblown fabrics are generally very soft and drapeable yet usually lack the requisite barrier properties. The lack of sufficient barrier properties in polyethylene meltblown fabrics is thought to be due to the inability to form uniformly fine fibers or due to the tendency to generate "shot", an imperfection which causes gaps or holes in the webs.
SU1~ARY OF THE INVENTION
This invention provides a meltblown fabric which has barrier properties comparable to polypropylene meltblown fabric yet with the softness and drapeability comanon to polyethylene fabrics.
A nonwoven fabric is provided which has barrier properties comparable to polypropylene meltblown fabrics yet has a softer hand than polypropylene and good breathability. This fabric is provided through a process of producing a soft nonwoven barrier fabric comprising the steps of melting at least one thermoplastic polyethylene polymer which has a density in the range of about 0.86 to about 0.97 grams/cc, extruding the polymer through fine openings, drawing said polymer to produce fibers, and depositing the fiberized polymer on a collecting surface to form a web of disbursed fibers, wherein the web has a hydrohead of at least 40 centimeters, and a cup crush peak load value of less than 40 grams. Such a web usually has a Frazier Porosity of less than 300 ft3/ft2/min.
The fabric may be laminated with spunbond layers of which one may be pre-bonded and may also be composed of bicomponent fibers.
The nonwoven fabric of this invention may be used in 5 products such as, for example, diapers, training pants, feminine hygiene products, adult incontinence products, wound dressings, bandages, sterilization wraps, surgical drapes and gowns and wipers . One specif is area in which the nonwoven fabric of this invention is useful is as a 10 leakage barrier in personal care items as an outer cover, leg cuffs and containment flaps.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic illustration of an apparatus which may be utilized to form the nonwoven web of the present invention.
Figure 2 is a bottom view of the die of Figure 1 with the die having been rotated 90 degrees for clarity.
Figure 3 is a cross-sectional view of the die of Figure 1 taken along line 3--3 of Figure 2.
DETAILED DESCRIPTION OF THE INVENTION
DEFINITIONS
As used herein the term "polymer" generally includes but is not limited to, homopolymers, copolymers (such as for example, block, graft, random and alternating copolymers), terpolymers, etc. and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term "polymer" shall include all possible geometrical configurations of the material. These configurations include, but are not limited to isotactic, syndiotactic and random symmetries.
As used herein the term "microfibers" means small diameter fibers having an average diameter not greater than about 75 microns, for example, having an average diameter of from about 0.5 microns to about 50 microns, or more particularly, microfibers may have an average diameter of from about 2 microns to about 40 microns.
As used herein the term "nonwoven fabric or web" means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs have been formed from many processes such as for example, meltblowing processes, spunbonding processes, and bonded carded web processes.
Docket #: 10,994 POLYETHYLENE MELTBLOWN FABRIC WITH BARRIER PROPERTIES
BACKGROUND OF THE INVENTION
This invention relates generally to a nonwoven fabric or web which is formed from meltblown fibers of thermoplastic polyethylene resin, as well as the process of producing such a fabric.
Thermoplastic resins have been extruded to form fibers and webs for a number of years. The most common thermoplastics for this application are polyolefins, particularly polypropylene. Other materials such as polyesters, polyetheresters, polyamides and polyurethanes are also used for this purpose. Each material has its characteristic advantages and disadvantages vis a vis the properties desired in the final product to be made from such fibers.
Nonwoven fabrics are useful for a wide variety of applications such as diapers, feminine hygiene products, incontinence products, towels, medical garments and many others. The nonwoven fabrics used in these applications are often in the form of laminates like spunbond/meltblown/spunbond (SMS) laminates. In SMS
laminates the exterior layers are generally spunbond polypropylene which are usually present for strength, and the interior layer which is generally meltblown polypropylene and is usually present as a barrier layer.
It is desirable that the meltblown barrier fabric layer have good barrier properties yet also be as soft and drapeable as possible. Polypropylene meltblown fabrics, while usually possessing good barrier properties, are not as soft and drapeable as polyethylene fabrics.
Polyethylene meltblown fabrics are generally very soft and drapeable yet usually lack the requisite barrier properties. The lack of sufficient barrier properties in polyethylene meltblown fabrics is thought to be due to the inability to form uniformly fine fibers or due to the tendency to generate "shot", an imperfection which causes gaps or holes in the webs.
SU1~ARY OF THE INVENTION
This invention provides a meltblown fabric which has barrier properties comparable to polypropylene meltblown fabric yet with the softness and drapeability comanon to polyethylene fabrics.
A nonwoven fabric is provided which has barrier properties comparable to polypropylene meltblown fabrics yet has a softer hand than polypropylene and good breathability. This fabric is provided through a process of producing a soft nonwoven barrier fabric comprising the steps of melting at least one thermoplastic polyethylene polymer which has a density in the range of about 0.86 to about 0.97 grams/cc, extruding the polymer through fine openings, drawing said polymer to produce fibers, and depositing the fiberized polymer on a collecting surface to form a web of disbursed fibers, wherein the web has a hydrohead of at least 40 centimeters, and a cup crush peak load value of less than 40 grams. Such a web usually has a Frazier Porosity of less than 300 ft3/ft2/min.
The fabric may be laminated with spunbond layers of which one may be pre-bonded and may also be composed of bicomponent fibers.
The nonwoven fabric of this invention may be used in 5 products such as, for example, diapers, training pants, feminine hygiene products, adult incontinence products, wound dressings, bandages, sterilization wraps, surgical drapes and gowns and wipers . One specif is area in which the nonwoven fabric of this invention is useful is as a 10 leakage barrier in personal care items as an outer cover, leg cuffs and containment flaps.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic illustration of an apparatus which may be utilized to form the nonwoven web of the present invention.
Figure 2 is a bottom view of the die of Figure 1 with the die having been rotated 90 degrees for clarity.
Figure 3 is a cross-sectional view of the die of Figure 1 taken along line 3--3 of Figure 2.
DETAILED DESCRIPTION OF THE INVENTION
DEFINITIONS
As used herein the term "polymer" generally includes but is not limited to, homopolymers, copolymers (such as for example, block, graft, random and alternating copolymers), terpolymers, etc. and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term "polymer" shall include all possible geometrical configurations of the material. These configurations include, but are not limited to isotactic, syndiotactic and random symmetries.
As used herein the term "microfibers" means small diameter fibers having an average diameter not greater than about 75 microns, for example, having an average diameter of from about 0.5 microns to about 50 microns, or more particularly, microfibers may have an average diameter of from about 2 microns to about 40 microns.
As used herein the term "nonwoven fabric or web" means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs have been formed from many processes such as for example, meltblowing processes, spunbonding processes, and bonded carded web processes.
~~3Q~~~
As used herein the term "spunbonded fibers" refers to small diameter fibers which are formed by extruding molten thermoplastic polymer material as filaments from a plurality of fine, usually circular capillaries of a spinnerette with the diameter of the extruded filaments then being rapidly reduced as by, for example, in U.S.
Patent no. 4,340,563 to Appel et al., and U.S. Patent no.
3,692,618 to Dorschner et al., U.S. Patent no. 3,802,817 to Matsuki et al., U.S. Patent nos. 3,338,992 and 3,341,394 to Kinney, U.S. Patent nos. 3,502,763 and 3,909,009 to Levy, and U.S. Patent no. 3,542,615 to Dobo et al. Spunbond fibers are generally continuous and larger than 7 microns, more particularly, having an average diameter of greater than 10 microns.
As used herein the term "meltblown fibers " means fibers formed by extruding a molten thermoplastic polymer through a plurality of fine, usually circular, die capillaries as molten threads or filaments into a high velocity gas (e.g. air) stream which attenuates the filaments of molten thermoplastic polymer material to reduce their diameter, which may be to microfiber diameter.
Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S.
Patent no. 3,849,241 to Butin and U.S. Patent 3,978,185.
As used herein the term "bicomponent" refers to fibers which have been formed from at least two polymers extruded from separate extruders but spun together to form one fiber. The configuration of such a bicomponent fiber may be a sheath/core arrangement wherein one polymer is surrounded by another or may be a side by side arrangement or an "islands-in-the-sea" arrangement. The ratio of the polymers used in a bicomponent fiber may be 75/25, 50/50, 25/75, etc.
As used herein, the term "bonding window" means the range of temperature of the calender rolls or other heating ~13~~4 means used to bond the nonwoven fabric together, over which such bonding is successful. For polypropylene spunbond, this calender bonding window is typically from about 260°F
to about 310°F (125°C to 154°C). Below about 260°F
the polypropylene is not hot enough to melt and bond and above about 310°F the polypropylene will melt excessively and can stick to the calender rolls. Polyethylene has an even narrower bonding window.
As used herein, the term "stitchbonded" means, for example, the stitching of a material in accordance with U.S. Patent 4,891,957 to Strack et al.
As used herein, the term "garment" means any type of apparel which may be worn. This includes industrial work wear and coveralls, undergarments, pants, shirts, jackets, gloves, socks, and the like.
As used herein, the term "medical product" means surgical gowns and drapes, face masks, head coverings, shoe coverings, wound dressings, bandages, sterilization wraps, wipers and the like.
As used herein, the term "personal care product" means diapers, training pants, absorbent underpants, adult incontinence products, and feminine hygeine products and the like.
As used herein, the term "outdoor fabric" means a fabric which is primarily, though not exclusively, used outdoors. The applications for which this fabric may be used include car covers, boat covers, airplane covers, camper/trailer fabric, furniture covers, awnings, canopies, tents, agricultural fabrics and outdoor apparel.
TEST METHODS
Cup Crush: The softness of a nonwoven fabric may be measured according to the "cup crush" test. The cup crush test evaluates fabric stiffness by measuring the peak load and peak energy required for a 4.5 cm diameter hemispherically shaped foot to crush a 23 cm by 23 cm piece ~13~~~~
of fabric shaped into an approximately 6.5 cm diameter by 6.5 cm tall inverted cup while the cup shaped fabric is surrounded by an approximately 6.5 cm diameter cylinder to maintain a uniform deformation of the cup shaped fabric.
The foot and the cup are aligned to avoid contact between the cup walls and the foot which could affect the peak load. The peak load is measured while the foot is descending at a rate of about 0.25 inches per second (38 cm per minute). A lower cup crush value indicates a softer laminate. A suitable device for measuring cup crush is a model FTD-G-500 load cell (500 gram range) available from the Schaevitz Company, Pennsauken, NJ. Cup crush load is measured in grams. Cup Crush energy is measured in gm-mm.
Hydrohead: A measure of the liquid barrier properties of a fabric is the hydrohead test. The hydrohead test determines the height of water (in centimeters) which the fabric will support before a predetermined amount of liquid passes through. A fabric with a higher hydrohead reading indicates it has a greater barrier to liquid penetration than a fabric with a lower hydrohead. The hydrohead test is performed according to Federal Test Standard No. 191A, Method 5514.
Frazier Porosity: A measure of the breathability of a fabric is the Frazier Porosity which is performed according to Federal Test Standard No. 191A, Method 5450.
Frazier Porosity measures the air flow rate through a fabric in cubic feet of air per square foot of fabric per minute or ft3/ft2/min. (Convert ft3/ftz/min to liters per square meter per minute (1/m2/min) by multiplying by 304.8) .
Melt Flow Rate: The melt flow rate (MFR) is a measure of the viscosity of a polymer. The MFR is expressed as the weight of material which flows from a capillary of known dimensions under a specified load or shear rate for a measured period of time and is measured in grams/10 minutes at 190°C according to, for example, ASTM test 1238, condition E.
The fibers from which the fabric of this invention is made are produced by the meltblowing process which is known in the art and is described in, for example, U. S . Patent no. 3,849,241 to Butin and U.S. Patent 3,978,185.
The meltblowing process generally uses an extruder to supply melted polymer to a die tip where the polymer is fiberized as it passes through fine openings, forming a curtain of filaments. The filaments are drawn pneumatically and deposited on a moving foraminous mat, belt or "forming wire" to form the nonwoven fabric.
Nonwoven fabrics may be measured in ounces per square yard (osy) or grams per square meter (gsm). (Multiplying osy by 33.91 yields gsm.) The fibers produced in the meltblowing process are generally in the range of from about 0.5 to about 10 microns in diameter, depending on process conditions and the desired end use for the fabrics to be produced from such fibers. For example, increasing the polymer molecular weight or decreasing the processing temperature results in larger diameter fibers. Changes in the quench fluid temperature and pneumatic draw pressure can also affect fiber diameter. Finer fibers are generally more desirable as they usually produce greater barrier properties in the fabric into which they are made.
The fabric of this invention may be used in a single layer embodiment or as a multilayer laminate incorporating the fabric of this invention. Such a laminate may be formed by a number of different techniques including but not limited to using adhesive, needle punching, ultrasonic bonding, print bonding, thermal calendering and any other method known in the art. Such a multilayer laminate may be an embodiment wherein some of the layers are spunbond and some meltblown such as a spunbond/meltblown (SM) laminate or a spunbond/meltblown/spunbond (SMS) laminate, as disclosed in U.S. Patent no. 4,041,203 to Brock et al. and U.S. Patent no. 5,169,706 to Collier, et al. or wherein some of the layers are made from staple fibers. The fibers used in the other layers may be polyethylene, polypropylene or bicomponent fibers.
An SMS laminate, for example, may be made by sequentially depositing onto a moving conveyor belt or forming wire first a spunbond fabric layer, then a meltblown fabric layer and last another spunbond layer and then bonding the laminate in a manner described above.
Alternatively, the three fabric layers may be made individually, collected in rolls, and combined in a separate bonding step.
In thermal calendering, various patterns for calender rolls have been developed. One example is the Hansen Pennings pattern with between about 10 and 25% bond area with about 100 to 500 bonds/square inch as taught in U.S.
Patent 3,855,046 to Hansen and Pennings. Another common pattern is a diamond pattern with repeating and slightly offset diamonds. Bond pattern and coverage area can vary considerably depending on the use to which the fabric will be put.
When the fabric of this invention is used as an SMS
laminate, it has been found to be advantageous to "pre-bond" one of the spunbond layers. Pre-bonding is a step of (thermally) bonding a layer by itself using a pattern of 8 to 50% bond area or more particularly a pattern of about 25% bond area with many small pins. Pre-bonding is advantageous with polyethylene webs because of the relatively high heat of fusion and low melting point of polyethylene. It is believed that in order to supply enough heat to a polyethylene web to bond it, the heat addition must be done sufficiently slowly to avoid excessively melting the web and causing it to stick to the calender rolls. Pre-bonding one of the spunbond layers helps to reduce the intensity of temperature the laminate must be subjected to in the bonding step.
Pre-bonding also provides the fabric with greater abrasion resistance though it can reduce the drapeability somewhat. Since the web should provide good barrier properties yet be soft and drapeable, pre-bonding should be kept to a minimum. Pre-bonding is optional and if desired should be restricted to only one layer for this reason.
After pre-bonding, the spunbond layer may then be combined with unbonded meltblown and spunbond layers and bonded with a more open bond pattern like the one mentioned above, preferably with a pattern having relatively larger pins. The temperature of bonding will vary depending on the exact polymers involved, the degree and strength of bonding desired, and the final use of the fabric.
The fabric of this invention may also be laminated with films, staple fibers, paper, and other commonly used materials.
Areas in which the fabric of this invention may find utility are garments, personal care products and medical products. ' The particular components of the personal care products where this fabric may be used are as leakage barriers such as containment flaps, outer covers and leg cuffs. Wipers may be for industrial use or for home use as countertop or bathroom wipes. Sterilization of the fabric for use as a sterile wrap should, of course, take place at a temperature lower than the melting point of any of the polymers used in the fabric or by alternative means such as gamma or other radiation techniques.
Turning now to the figures, particularly figure 1, it can be seen that an apparatus for forming the nonwoven web of this invention is represented by the reference number 10.
In farming the nonwoven web of the present invention, pellets, beads or chips (not shown) of a suitable material are introduced into a hopper 12 of an extruder 14. The extruder 14. has an extrusion screw (not shown) which is driven by a conventional drive motor (not shown). As the material advances through the extruder 14, due to rotation of the extrusion screw by the drive motor, it is progressively heated to a molten state. Heating of the material may be accomplished in a plurality of discrete steps with its temperature being gradually elevated as it advances through discrete heating zones of the extruder 14 toward a meltblowing die 16. The die 16 may yet be another heating zone where the temperature of the thermoplastic resin is maintained at an elevated level for extrusion.
The temperature which will be required to heat the material to a molten state will vary somewhat depending upon exactly which material is utilized and can be readily determined by those in the art.
Figure 2 illustrates that the lateral extent 18 of the die 16 is provided with a plurality of orifices 20 which are usually circular in cross-section and are linearly arranged along the extent 18 of the tip 22 of the die 16.
The orifices 20 of the die 16 may have diameters that range from about 0.01 of an inch to about 0.02 of an inch and a length which may range from about 0.05 inches to about 0.30 inches. For example, the orifices may have a diameter of about 0.0145 inches and a length of about 0.113 inches.
From about 5 to about 50 orifices may be provided per inch of the lateral extent 18 of the tip 22 of the die 16 with the die 16 extending from abut 20 inches to about 60 inches or more. Figure 1 illustrates that the molten material emerges from the orifices 20 of the die 16 as molten strands or threads 24.
Figure 3, which is a cross-sectional view of the die of Figure 2 taken along line 3--3, illustrates that the die 16 preferably includes attenuating gas sources 30 and 32 (see Figures 1 & 2). The heated, pressurized attenuating gas enters the die 16 at the inlets 26, 28 and follows a path generally designated by arrows 34, 36 through the two chambers 38, 40 and on through the two narrow passageways or gaps 42, 44 so as to contact the extruded threads 24 as they exit the orifices 20 of the die 16. The chambers 38, are designed so that the heated attenuating gas passes through the chambers 38, 4o and exits the gaps 42, 44 to ~I~Q~46 form a stream (not shown) of attenuating gas which exits the die 16 on both sides of the threads 24. The temperature and pressure of the heated stream of attenuating gas can vary widely. For example, the heated attenuating gas can be applied at a temperature of from about 220 to about 315°C (425-600°F), more particularly, from about 230 to about 280°C. The heated attenuating gas may generally be applied at a pressure of from about 0.5 pounds per square inch gage (psig) to about 20 psig. More particularly, from about 1 to about 10 psig.
The position of the air plates 46, 48 which, in conjunction with a die portion 50 define the chambers 38, 40 and the gaps 42, 44, may be adjusted relative to the die portion 50 to increase or decrease the width of the attenuating gas passageways 42 , 44 so that the volume of attenuating gas passing through the air passageways 42, 44 during a given time period can be varied without varying the velocity of the attenuating gas. Furthermore, the air plates 46, 48 may be adjusted to effect a "recessed" die tip configuration as illustrated in Figure 3, or a positive die tip 22 stick out configuration wherein the tip of the die portion 50 protrudes beyond the plane formed by the plates 48. Lower attenuating gas velocities and wider air passageway gaps are generally preferred if substantially continuous meltblown fibers or microfibers 24 are to be produced.
The two streams of attenuating gas converge to form a stream of gas which entrains and attenuates the molten threads 24, as they exit the orifices 20, into fibers or , depending on the degree of attenuation, microfibers of a small diameter which is usually less than the diameter of the orifices 20. The gas-borne fibers or microfibers 24 are blown, by the action of the attenuating gas, onto a collecting arrangement which, in the embodiment illustrated in Figure 1, is a foraminous endless belt 52 conventionally driven by rollers 54. Other foraminous arrangements such as a rotating drum could be used. One or more vacuum boxes (not shown) may be located below the surface of the foraminous belt 52 and between the rollers 54. The fibers or microfibers 24 are collected as a coherent matrix of fibers on the surface of the endless belt 52 which is rotating as indicated by the arrow 58 in Figure 1. The vacuum boxes assist in retention of the matrix on the surface~of the belt 52. Typically, the tip 22 of the die 16 is from about 6 inches to about 14 inches from the surface of the foraminous belt 52 upon which the fibers are collected. The thus collected, entangled fibers or microfibers 24 are coherent and may be removed from the belt 52 as.a self-supporting nonwoven web 56.
A number of process modifications were found to be helpful in order to produce the fabric of this invention.
For example, the forming wire used in the practice of this invention should be of a finer mesh than that used for polypropylene meltblown fabric. In addition, the distance from the die tip to the forming wire or the "forming distance" should be reduced to about 7 inches (18 cm).
Polymers useful in the meltblowing process generally have a process melt temperature of between about 406°F to about 608°F (208°C to 320°C). Meltblown fibers for the practice of this invention are produced from particular polyethylene resins under particular operating conditions.
A particularly well suited polyethylene~which may be used in this invention is available from the Dow Chemical Company of Freeport, Texas under the trade-mark Aspun~.
Aspun~ designates a family of linear low density polyethylene resins. Acceptable resins are disclosed in U.S. Patent 4,830,907 and are comprised of copolymers of ethylene with at least one alpha-olefin of C3 to C~z and have a density in the range of about 0.86 to 0.97 grams/cc and a melt flow rate in the range of about 0.01 to about 400 grams/l0 minutes.
Any layer of a fabric of this invention may contain a fluorocarbon chemical to enhance chemical repellency which may be any of those taught in U.S. patent 5,178,931, column 7, line 40 to column 8, line 60. A particularly well suited additive is FX-1801, formerly called L-10307,Mwhich is available from the 3M Company of St. Paul, Minnesota.
This material is identified as Additive M in the above cited patent and as having a melting point of about 130 to 138°C. This material may be added to a layer or layers at an amount of about 0.1 to about 2.0 weight percent or more particularly between about o.25 and 1.0 weight percent. As noted in the above patent, the fluorocarbon additive is an internal additive, as differentiated from a topically applied additive, and preferentially migrates to the surface of the fibers as they are formed.
The layers of the fabric of this invention may also contain fire retardants for increased resistance to fire and/or pigments to give each layer the same or distinct colors. Fire retardants and pigments for spunbond and meltblown thermoplastic polymers are known in the art and are internal additives. A pigment, if used, is generally present in an amount less than 5 weight percent of the layer.
The fabric of this invention may also have topical treatments applied to it for more specialized functions.
Such topical treatments and their methods of application are known in the art and include, for example, alcohol repellancy treatments, anti-static treatments and the like, applied by spraying, dipping, etc. An example of such a topical treatment is the application of Zelec~ antistat (available from E.I. duPont, Wilmington, Delaware).
The following Examples show the characteristics of fabrics which satisfy the requirements of this invention versus those that do not. Note that Examples 1, 4 & 5 are examples of the fabric of this invention, the others are not. The meltblown webs of this invention exhibit the fiber fineness and lack of shot required to produce hydrohead values of greater than 40 cm, cup crush peak load values of less than 40 grams and where the web usually has ~~.~Q~4~
a Frazier Porosity of less than 300 ft3/ftZ/min. The SMS
laminates using the meltblown web of this invention have a hydrohead of at least 50 centimeters and a cup crush peak load value of less than 125 grams.
Meltblown fibers were produced from Dow's Aspun~ XUR-1567-45766-30A linear low density polyethylene resin. The polymer melt temperature was about 500°F (260°C), as was the drawing air which flowed at about '420 SCFM. The throughput was about 2 pounds per die plate inch per hour (357 gm/cm/hour) to produce a fabric with a basis weig~~ of about 0.5 osy (17 gsm). The distance from the die tip to the forming~wire was about 6 inches (15 cm).
The results are shown in Table 1.
Meltblown fibers were produced from Dow's 61800.31 polyethylene resin. The polymer temperature was about 500°F (260°C), and the drawing air which flowed at about 315 SCFM was at a temperature of about 540°F. The throughput was about 2 pounds per die plate inch per hour (357 gm/cm/hour) to produce a fabric with a basis weight of about 0.7 osy (24 gsm). The distance from the die tip to the forming wire was about 8.5 inches (22 cm).
The results are shown in Table 1.
Meltblown fibers were produced from Dow's 61800.31 polyethylene resin, the same polymer as in Example 2, at slightly different conditions. The polymer temperature was about 500°F (260°C), and the drawing air which flowed at about 300 SCFM was at a temperature of about 510 ° F. The throughput was about 2 pounds per die plate inch per hour (357 gm/cm/hour) to produce a fabric with a basis weight of about 0.5 osy.
The results are shown in Table 1.
Meltblown fibers were produced from Himont PF015 polypropylene resin. The polymer temperature was about 520°F (270°C), and the drawing air which flowed at about 370 SCFM was at a temperature of about 525°F. The throughput was about 3 pounds per die plate inch per hour (536 gm/cm/hour) to produce a fabric with a basis weight of about 0.5 osy (17 gsm). The distance from the die tip to the forming wire was about 9 inches (23 cm).
The results are shown in Table 1.
An SMS laminated fabric was produced. The spunbond layers were sheath/core bicomponent fibers with polyethylene as the sheath and polypropylene as the core.
The polyethylene used in the spunbond layer was Dow's Aspun~ 6811A and the polypropylene was from the Exxon Chemical Company of Baytown, Texas, and designated 3445.
The spunbond melt temperature was about 430°F (221°C) and the throughput was 0.5 grams/hole/minute (ghm) to produce of fiber of 2.1 denier.
One of the spunbond layers was pre-bonded with a Hansen Pennings pattern with about 25% bond area at a temperature of about 270°F.
The meltblown layer was the material of Example 1 above.
The layers were laminated together using an expanded Hansen-Pennings pattern at 300°F. The basis weight of the SMS fabric was 1.6 osy (54 gsm).
The results are shown in Table 1.
An SMS laminated fabric was produced like that in Example 4 using the same polymers. The spunbond melt temperature was about 440°F (227°C) and the throughput was 0.4 grams/hole/minute (ghm) to produce of fiber of 1.1 denier.
One of the spunbond layers was pre-bonded with a Hansen Pennings pattern with about 25% bond area at a temperature of about 255°F.
The layers were laminated together at a temperature of about 280°F (138°C) using an expanded Hansen-Penning pattern. The basis weight of the fabric was 1.6 osy (54 gsm).
The results are shown in Table 1.
An SMS laminated fabric was produced. The spunbond layers were polypropylene homofiber. The polypropylene was Exxon's 9355 at a melt temperature of 420°F (216°C) and a throughput of 0.7 ghm for a fiber of 2.5 denier. The meltblown layer was the material of Example 3 above.
The layers were~laminated together at a temperature of about 270°F (132°C) using a wire weave pattern. The basis weight of the fabric was 1.6 osy (54 gsm).
The results are shown in Table 1.
Example Hvdrohead Frazier Cu_~o Crush Peak Load Energy 2A 25 230 na na The results surprisingly show that fabrics made from fibers spun from polymers useful in this invention can have barrier properties comparable to and even somewhat better than conventional polypropylene fibers while having a softer feel and good breathability.
This invention desirably combines the good barrier properties associated with polypropylene meltblown fabrics with the softness associated with polyethylene meltblown fabrics to produce a soft, high barrier, fabric.
As used herein the term "spunbonded fibers" refers to small diameter fibers which are formed by extruding molten thermoplastic polymer material as filaments from a plurality of fine, usually circular capillaries of a spinnerette with the diameter of the extruded filaments then being rapidly reduced as by, for example, in U.S.
Patent no. 4,340,563 to Appel et al., and U.S. Patent no.
3,692,618 to Dorschner et al., U.S. Patent no. 3,802,817 to Matsuki et al., U.S. Patent nos. 3,338,992 and 3,341,394 to Kinney, U.S. Patent nos. 3,502,763 and 3,909,009 to Levy, and U.S. Patent no. 3,542,615 to Dobo et al. Spunbond fibers are generally continuous and larger than 7 microns, more particularly, having an average diameter of greater than 10 microns.
As used herein the term "meltblown fibers " means fibers formed by extruding a molten thermoplastic polymer through a plurality of fine, usually circular, die capillaries as molten threads or filaments into a high velocity gas (e.g. air) stream which attenuates the filaments of molten thermoplastic polymer material to reduce their diameter, which may be to microfiber diameter.
Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S.
Patent no. 3,849,241 to Butin and U.S. Patent 3,978,185.
As used herein the term "bicomponent" refers to fibers which have been formed from at least two polymers extruded from separate extruders but spun together to form one fiber. The configuration of such a bicomponent fiber may be a sheath/core arrangement wherein one polymer is surrounded by another or may be a side by side arrangement or an "islands-in-the-sea" arrangement. The ratio of the polymers used in a bicomponent fiber may be 75/25, 50/50, 25/75, etc.
As used herein, the term "bonding window" means the range of temperature of the calender rolls or other heating ~13~~4 means used to bond the nonwoven fabric together, over which such bonding is successful. For polypropylene spunbond, this calender bonding window is typically from about 260°F
to about 310°F (125°C to 154°C). Below about 260°F
the polypropylene is not hot enough to melt and bond and above about 310°F the polypropylene will melt excessively and can stick to the calender rolls. Polyethylene has an even narrower bonding window.
As used herein, the term "stitchbonded" means, for example, the stitching of a material in accordance with U.S. Patent 4,891,957 to Strack et al.
As used herein, the term "garment" means any type of apparel which may be worn. This includes industrial work wear and coveralls, undergarments, pants, shirts, jackets, gloves, socks, and the like.
As used herein, the term "medical product" means surgical gowns and drapes, face masks, head coverings, shoe coverings, wound dressings, bandages, sterilization wraps, wipers and the like.
As used herein, the term "personal care product" means diapers, training pants, absorbent underpants, adult incontinence products, and feminine hygeine products and the like.
As used herein, the term "outdoor fabric" means a fabric which is primarily, though not exclusively, used outdoors. The applications for which this fabric may be used include car covers, boat covers, airplane covers, camper/trailer fabric, furniture covers, awnings, canopies, tents, agricultural fabrics and outdoor apparel.
TEST METHODS
Cup Crush: The softness of a nonwoven fabric may be measured according to the "cup crush" test. The cup crush test evaluates fabric stiffness by measuring the peak load and peak energy required for a 4.5 cm diameter hemispherically shaped foot to crush a 23 cm by 23 cm piece ~13~~~~
of fabric shaped into an approximately 6.5 cm diameter by 6.5 cm tall inverted cup while the cup shaped fabric is surrounded by an approximately 6.5 cm diameter cylinder to maintain a uniform deformation of the cup shaped fabric.
The foot and the cup are aligned to avoid contact between the cup walls and the foot which could affect the peak load. The peak load is measured while the foot is descending at a rate of about 0.25 inches per second (38 cm per minute). A lower cup crush value indicates a softer laminate. A suitable device for measuring cup crush is a model FTD-G-500 load cell (500 gram range) available from the Schaevitz Company, Pennsauken, NJ. Cup crush load is measured in grams. Cup Crush energy is measured in gm-mm.
Hydrohead: A measure of the liquid barrier properties of a fabric is the hydrohead test. The hydrohead test determines the height of water (in centimeters) which the fabric will support before a predetermined amount of liquid passes through. A fabric with a higher hydrohead reading indicates it has a greater barrier to liquid penetration than a fabric with a lower hydrohead. The hydrohead test is performed according to Federal Test Standard No. 191A, Method 5514.
Frazier Porosity: A measure of the breathability of a fabric is the Frazier Porosity which is performed according to Federal Test Standard No. 191A, Method 5450.
Frazier Porosity measures the air flow rate through a fabric in cubic feet of air per square foot of fabric per minute or ft3/ft2/min. (Convert ft3/ftz/min to liters per square meter per minute (1/m2/min) by multiplying by 304.8) .
Melt Flow Rate: The melt flow rate (MFR) is a measure of the viscosity of a polymer. The MFR is expressed as the weight of material which flows from a capillary of known dimensions under a specified load or shear rate for a measured period of time and is measured in grams/10 minutes at 190°C according to, for example, ASTM test 1238, condition E.
The fibers from which the fabric of this invention is made are produced by the meltblowing process which is known in the art and is described in, for example, U. S . Patent no. 3,849,241 to Butin and U.S. Patent 3,978,185.
The meltblowing process generally uses an extruder to supply melted polymer to a die tip where the polymer is fiberized as it passes through fine openings, forming a curtain of filaments. The filaments are drawn pneumatically and deposited on a moving foraminous mat, belt or "forming wire" to form the nonwoven fabric.
Nonwoven fabrics may be measured in ounces per square yard (osy) or grams per square meter (gsm). (Multiplying osy by 33.91 yields gsm.) The fibers produced in the meltblowing process are generally in the range of from about 0.5 to about 10 microns in diameter, depending on process conditions and the desired end use for the fabrics to be produced from such fibers. For example, increasing the polymer molecular weight or decreasing the processing temperature results in larger diameter fibers. Changes in the quench fluid temperature and pneumatic draw pressure can also affect fiber diameter. Finer fibers are generally more desirable as they usually produce greater barrier properties in the fabric into which they are made.
The fabric of this invention may be used in a single layer embodiment or as a multilayer laminate incorporating the fabric of this invention. Such a laminate may be formed by a number of different techniques including but not limited to using adhesive, needle punching, ultrasonic bonding, print bonding, thermal calendering and any other method known in the art. Such a multilayer laminate may be an embodiment wherein some of the layers are spunbond and some meltblown such as a spunbond/meltblown (SM) laminate or a spunbond/meltblown/spunbond (SMS) laminate, as disclosed in U.S. Patent no. 4,041,203 to Brock et al. and U.S. Patent no. 5,169,706 to Collier, et al. or wherein some of the layers are made from staple fibers. The fibers used in the other layers may be polyethylene, polypropylene or bicomponent fibers.
An SMS laminate, for example, may be made by sequentially depositing onto a moving conveyor belt or forming wire first a spunbond fabric layer, then a meltblown fabric layer and last another spunbond layer and then bonding the laminate in a manner described above.
Alternatively, the three fabric layers may be made individually, collected in rolls, and combined in a separate bonding step.
In thermal calendering, various patterns for calender rolls have been developed. One example is the Hansen Pennings pattern with between about 10 and 25% bond area with about 100 to 500 bonds/square inch as taught in U.S.
Patent 3,855,046 to Hansen and Pennings. Another common pattern is a diamond pattern with repeating and slightly offset diamonds. Bond pattern and coverage area can vary considerably depending on the use to which the fabric will be put.
When the fabric of this invention is used as an SMS
laminate, it has been found to be advantageous to "pre-bond" one of the spunbond layers. Pre-bonding is a step of (thermally) bonding a layer by itself using a pattern of 8 to 50% bond area or more particularly a pattern of about 25% bond area with many small pins. Pre-bonding is advantageous with polyethylene webs because of the relatively high heat of fusion and low melting point of polyethylene. It is believed that in order to supply enough heat to a polyethylene web to bond it, the heat addition must be done sufficiently slowly to avoid excessively melting the web and causing it to stick to the calender rolls. Pre-bonding one of the spunbond layers helps to reduce the intensity of temperature the laminate must be subjected to in the bonding step.
Pre-bonding also provides the fabric with greater abrasion resistance though it can reduce the drapeability somewhat. Since the web should provide good barrier properties yet be soft and drapeable, pre-bonding should be kept to a minimum. Pre-bonding is optional and if desired should be restricted to only one layer for this reason.
After pre-bonding, the spunbond layer may then be combined with unbonded meltblown and spunbond layers and bonded with a more open bond pattern like the one mentioned above, preferably with a pattern having relatively larger pins. The temperature of bonding will vary depending on the exact polymers involved, the degree and strength of bonding desired, and the final use of the fabric.
The fabric of this invention may also be laminated with films, staple fibers, paper, and other commonly used materials.
Areas in which the fabric of this invention may find utility are garments, personal care products and medical products. ' The particular components of the personal care products where this fabric may be used are as leakage barriers such as containment flaps, outer covers and leg cuffs. Wipers may be for industrial use or for home use as countertop or bathroom wipes. Sterilization of the fabric for use as a sterile wrap should, of course, take place at a temperature lower than the melting point of any of the polymers used in the fabric or by alternative means such as gamma or other radiation techniques.
Turning now to the figures, particularly figure 1, it can be seen that an apparatus for forming the nonwoven web of this invention is represented by the reference number 10.
In farming the nonwoven web of the present invention, pellets, beads or chips (not shown) of a suitable material are introduced into a hopper 12 of an extruder 14. The extruder 14. has an extrusion screw (not shown) which is driven by a conventional drive motor (not shown). As the material advances through the extruder 14, due to rotation of the extrusion screw by the drive motor, it is progressively heated to a molten state. Heating of the material may be accomplished in a plurality of discrete steps with its temperature being gradually elevated as it advances through discrete heating zones of the extruder 14 toward a meltblowing die 16. The die 16 may yet be another heating zone where the temperature of the thermoplastic resin is maintained at an elevated level for extrusion.
The temperature which will be required to heat the material to a molten state will vary somewhat depending upon exactly which material is utilized and can be readily determined by those in the art.
Figure 2 illustrates that the lateral extent 18 of the die 16 is provided with a plurality of orifices 20 which are usually circular in cross-section and are linearly arranged along the extent 18 of the tip 22 of the die 16.
The orifices 20 of the die 16 may have diameters that range from about 0.01 of an inch to about 0.02 of an inch and a length which may range from about 0.05 inches to about 0.30 inches. For example, the orifices may have a diameter of about 0.0145 inches and a length of about 0.113 inches.
From about 5 to about 50 orifices may be provided per inch of the lateral extent 18 of the tip 22 of the die 16 with the die 16 extending from abut 20 inches to about 60 inches or more. Figure 1 illustrates that the molten material emerges from the orifices 20 of the die 16 as molten strands or threads 24.
Figure 3, which is a cross-sectional view of the die of Figure 2 taken along line 3--3, illustrates that the die 16 preferably includes attenuating gas sources 30 and 32 (see Figures 1 & 2). The heated, pressurized attenuating gas enters the die 16 at the inlets 26, 28 and follows a path generally designated by arrows 34, 36 through the two chambers 38, 40 and on through the two narrow passageways or gaps 42, 44 so as to contact the extruded threads 24 as they exit the orifices 20 of the die 16. The chambers 38, are designed so that the heated attenuating gas passes through the chambers 38, 4o and exits the gaps 42, 44 to ~I~Q~46 form a stream (not shown) of attenuating gas which exits the die 16 on both sides of the threads 24. The temperature and pressure of the heated stream of attenuating gas can vary widely. For example, the heated attenuating gas can be applied at a temperature of from about 220 to about 315°C (425-600°F), more particularly, from about 230 to about 280°C. The heated attenuating gas may generally be applied at a pressure of from about 0.5 pounds per square inch gage (psig) to about 20 psig. More particularly, from about 1 to about 10 psig.
The position of the air plates 46, 48 which, in conjunction with a die portion 50 define the chambers 38, 40 and the gaps 42, 44, may be adjusted relative to the die portion 50 to increase or decrease the width of the attenuating gas passageways 42 , 44 so that the volume of attenuating gas passing through the air passageways 42, 44 during a given time period can be varied without varying the velocity of the attenuating gas. Furthermore, the air plates 46, 48 may be adjusted to effect a "recessed" die tip configuration as illustrated in Figure 3, or a positive die tip 22 stick out configuration wherein the tip of the die portion 50 protrudes beyond the plane formed by the plates 48. Lower attenuating gas velocities and wider air passageway gaps are generally preferred if substantially continuous meltblown fibers or microfibers 24 are to be produced.
The two streams of attenuating gas converge to form a stream of gas which entrains and attenuates the molten threads 24, as they exit the orifices 20, into fibers or , depending on the degree of attenuation, microfibers of a small diameter which is usually less than the diameter of the orifices 20. The gas-borne fibers or microfibers 24 are blown, by the action of the attenuating gas, onto a collecting arrangement which, in the embodiment illustrated in Figure 1, is a foraminous endless belt 52 conventionally driven by rollers 54. Other foraminous arrangements such as a rotating drum could be used. One or more vacuum boxes (not shown) may be located below the surface of the foraminous belt 52 and between the rollers 54. The fibers or microfibers 24 are collected as a coherent matrix of fibers on the surface of the endless belt 52 which is rotating as indicated by the arrow 58 in Figure 1. The vacuum boxes assist in retention of the matrix on the surface~of the belt 52. Typically, the tip 22 of the die 16 is from about 6 inches to about 14 inches from the surface of the foraminous belt 52 upon which the fibers are collected. The thus collected, entangled fibers or microfibers 24 are coherent and may be removed from the belt 52 as.a self-supporting nonwoven web 56.
A number of process modifications were found to be helpful in order to produce the fabric of this invention.
For example, the forming wire used in the practice of this invention should be of a finer mesh than that used for polypropylene meltblown fabric. In addition, the distance from the die tip to the forming wire or the "forming distance" should be reduced to about 7 inches (18 cm).
Polymers useful in the meltblowing process generally have a process melt temperature of between about 406°F to about 608°F (208°C to 320°C). Meltblown fibers for the practice of this invention are produced from particular polyethylene resins under particular operating conditions.
A particularly well suited polyethylene~which may be used in this invention is available from the Dow Chemical Company of Freeport, Texas under the trade-mark Aspun~.
Aspun~ designates a family of linear low density polyethylene resins. Acceptable resins are disclosed in U.S. Patent 4,830,907 and are comprised of copolymers of ethylene with at least one alpha-olefin of C3 to C~z and have a density in the range of about 0.86 to 0.97 grams/cc and a melt flow rate in the range of about 0.01 to about 400 grams/l0 minutes.
Any layer of a fabric of this invention may contain a fluorocarbon chemical to enhance chemical repellency which may be any of those taught in U.S. patent 5,178,931, column 7, line 40 to column 8, line 60. A particularly well suited additive is FX-1801, formerly called L-10307,Mwhich is available from the 3M Company of St. Paul, Minnesota.
This material is identified as Additive M in the above cited patent and as having a melting point of about 130 to 138°C. This material may be added to a layer or layers at an amount of about 0.1 to about 2.0 weight percent or more particularly between about o.25 and 1.0 weight percent. As noted in the above patent, the fluorocarbon additive is an internal additive, as differentiated from a topically applied additive, and preferentially migrates to the surface of the fibers as they are formed.
The layers of the fabric of this invention may also contain fire retardants for increased resistance to fire and/or pigments to give each layer the same or distinct colors. Fire retardants and pigments for spunbond and meltblown thermoplastic polymers are known in the art and are internal additives. A pigment, if used, is generally present in an amount less than 5 weight percent of the layer.
The fabric of this invention may also have topical treatments applied to it for more specialized functions.
Such topical treatments and their methods of application are known in the art and include, for example, alcohol repellancy treatments, anti-static treatments and the like, applied by spraying, dipping, etc. An example of such a topical treatment is the application of Zelec~ antistat (available from E.I. duPont, Wilmington, Delaware).
The following Examples show the characteristics of fabrics which satisfy the requirements of this invention versus those that do not. Note that Examples 1, 4 & 5 are examples of the fabric of this invention, the others are not. The meltblown webs of this invention exhibit the fiber fineness and lack of shot required to produce hydrohead values of greater than 40 cm, cup crush peak load values of less than 40 grams and where the web usually has ~~.~Q~4~
a Frazier Porosity of less than 300 ft3/ftZ/min. The SMS
laminates using the meltblown web of this invention have a hydrohead of at least 50 centimeters and a cup crush peak load value of less than 125 grams.
Meltblown fibers were produced from Dow's Aspun~ XUR-1567-45766-30A linear low density polyethylene resin. The polymer melt temperature was about 500°F (260°C), as was the drawing air which flowed at about '420 SCFM. The throughput was about 2 pounds per die plate inch per hour (357 gm/cm/hour) to produce a fabric with a basis weig~~ of about 0.5 osy (17 gsm). The distance from the die tip to the forming~wire was about 6 inches (15 cm).
The results are shown in Table 1.
Meltblown fibers were produced from Dow's 61800.31 polyethylene resin. The polymer temperature was about 500°F (260°C), and the drawing air which flowed at about 315 SCFM was at a temperature of about 540°F. The throughput was about 2 pounds per die plate inch per hour (357 gm/cm/hour) to produce a fabric with a basis weight of about 0.7 osy (24 gsm). The distance from the die tip to the forming wire was about 8.5 inches (22 cm).
The results are shown in Table 1.
Meltblown fibers were produced from Dow's 61800.31 polyethylene resin, the same polymer as in Example 2, at slightly different conditions. The polymer temperature was about 500°F (260°C), and the drawing air which flowed at about 300 SCFM was at a temperature of about 510 ° F. The throughput was about 2 pounds per die plate inch per hour (357 gm/cm/hour) to produce a fabric with a basis weight of about 0.5 osy.
The results are shown in Table 1.
Meltblown fibers were produced from Himont PF015 polypropylene resin. The polymer temperature was about 520°F (270°C), and the drawing air which flowed at about 370 SCFM was at a temperature of about 525°F. The throughput was about 3 pounds per die plate inch per hour (536 gm/cm/hour) to produce a fabric with a basis weight of about 0.5 osy (17 gsm). The distance from the die tip to the forming wire was about 9 inches (23 cm).
The results are shown in Table 1.
An SMS laminated fabric was produced. The spunbond layers were sheath/core bicomponent fibers with polyethylene as the sheath and polypropylene as the core.
The polyethylene used in the spunbond layer was Dow's Aspun~ 6811A and the polypropylene was from the Exxon Chemical Company of Baytown, Texas, and designated 3445.
The spunbond melt temperature was about 430°F (221°C) and the throughput was 0.5 grams/hole/minute (ghm) to produce of fiber of 2.1 denier.
One of the spunbond layers was pre-bonded with a Hansen Pennings pattern with about 25% bond area at a temperature of about 270°F.
The meltblown layer was the material of Example 1 above.
The layers were laminated together using an expanded Hansen-Pennings pattern at 300°F. The basis weight of the SMS fabric was 1.6 osy (54 gsm).
The results are shown in Table 1.
An SMS laminated fabric was produced like that in Example 4 using the same polymers. The spunbond melt temperature was about 440°F (227°C) and the throughput was 0.4 grams/hole/minute (ghm) to produce of fiber of 1.1 denier.
One of the spunbond layers was pre-bonded with a Hansen Pennings pattern with about 25% bond area at a temperature of about 255°F.
The layers were laminated together at a temperature of about 280°F (138°C) using an expanded Hansen-Penning pattern. The basis weight of the fabric was 1.6 osy (54 gsm).
The results are shown in Table 1.
An SMS laminated fabric was produced. The spunbond layers were polypropylene homofiber. The polypropylene was Exxon's 9355 at a melt temperature of 420°F (216°C) and a throughput of 0.7 ghm for a fiber of 2.5 denier. The meltblown layer was the material of Example 3 above.
The layers were~laminated together at a temperature of about 270°F (132°C) using a wire weave pattern. The basis weight of the fabric was 1.6 osy (54 gsm).
The results are shown in Table 1.
Example Hvdrohead Frazier Cu_~o Crush Peak Load Energy 2A 25 230 na na The results surprisingly show that fabrics made from fibers spun from polymers useful in this invention can have barrier properties comparable to and even somewhat better than conventional polypropylene fibers while having a softer feel and good breathability.
This invention desirably combines the good barrier properties associated with polypropylene meltblown fabrics with the softness associated with polyethylene meltblown fabrics to produce a soft, high barrier, fabric.
Claims (17)
1. A process of producing a soft nonwoven barrier fabric comprising the steps of:
melting at least one thermoplastic polyethylene polymer, said polymer having a density in the range of about 0.86 to about 0.97 grams/cc;
extruding said polymer through fine openings;
drawing said polymer to produce fibers; and depositing said fiberized polymer on a collecting surface to form a layer of meltblown disbursed fibers as a web, wherein said web has a hydrohead of at least 40 centimeters, and a cup crush peak load value of less than 40 grams.
melting at least one thermoplastic polyethylene polymer, said polymer having a density in the range of about 0.86 to about 0.97 grams/cc;
extruding said polymer through fine openings;
drawing said polymer to produce fibers; and depositing said fiberized polymer on a collecting surface to form a layer of meltblown disbursed fibers as a web, wherein said web has a hydrohead of at least 40 centimeters, and a cup crush peak load value of less than 40 grams.
2. A nonwoven fabric produced according to the process of claim 1 wherein said web has a Frazier Porosity of less than 300 ft3/ft2/min.
3. A nonwoven fabric produced according to the process of claim 1 further comprising the steps of adding a second layer of material to said layer of meltblown fibers and bonding the layers together.
4. The nonwoven fabric of claim 3 wherein said second layer is selected from the group consisting of spunbound fiber webs and staple fiber webs.
5. The nonwoven fabric of claim 4 wherein said second layer is comprised of fibers selected from the group consisting of polyethylene fibers, polypropylene fibers and polyethylene/polypropylene bicomponent fibers.
6. A nonwoven fabric laminate comprising a first layer, a second layer produced in accordance with process of claim 1, and a third layer, wherein said first and third layers are selected from the group consisting of spunbound fiber webs and staple fibers webs, and which has been bonded to form a laminate.
7. The nonwoven fabric of claim 6 wherein said first and third layers are comprised of fibers selected from the group consisting of polyethylene fibers, polypropylene fibers and polyethylene/polypropylene bicomponent fibers.
8. The nonwoven fabric laminate of claim 6 or 7 wherein said fabrics are bonded by thermal calender bonding.
9. The nonwoven fabric laminate of claim 6 or 7 wherein said fabrics are bonded by ultrasonic bonding.
10. The nonwoven fabric of anyone of claims 6 to 9 which is present in an item selected from the group consisting of garments, medical products, personal care products and outdoor fabrics.
11. The nonwoven fabric of anyone of claims 6 to 10 which is laminated to a material selected from the group consisting of films, glass fibers, staple fibers, and papers.
12. The nonwoven fabric laminate of claim 6 wherein one of said first and third layers has been pre-bonded.
13. The nonwoven fabric laminate of claim 7 wherein said first and third layer fibers are bicomponent fibers comprised of polyethylene and polypropylene in a sheath/core arrangement with the polyethylene as the sheath.
14. A process of producing a soft nonwoven barrier fabric comprising the steps of:
providing a polyethylene/polypropylene bicomponent sheath/core spunbound fiber web with polyethylene as the sheath as a first layer;
melting at least one thermoplastic polyethylene polymer, said polymer having a density in the range of about 0.86 to about 0.97 grams/cc;
extruding said polymer through fine openings;
drawing said polymer to produce fibers; and depositing said fiberized polymer on said web to form a layer of meltblown disbursed fibers as a second layer.
providing a polyethylene/polypropylene bicomponent sheath/core spunbound fiber web with polyethylene as the sheath as a first layer;
melting at least one thermoplastic polyethylene polymer, said polymer having a density in the range of about 0.86 to about 0.97 grams/cc;
extruding said polymer through fine openings;
drawing said polymer to produce fibers; and depositing said fiberized polymer on said web to form a layer of meltblown disbursed fibers as a second layer.
15. The process of producing the soft nonwoven barrier fabric of claim 14 further comprising the step of adding as a third layer a polyethylene/polypropylene bicomponent sheath/core spunbound fiber web to said first and second layers, with polyethylene as the sheath, against said second layer, wherein said fabric has a hydrohead of at least 50 centimeters and a cup crush peak load value of less than 125 grams.
16. The laminate of claim 15 which is present in an item selected from the group consisting of garments, medical products, personal care products and outdoor fabrics.
17. The laminate of claim 15 wherein said item is a medical product and said medical product is a surgical gown.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US215,220 | 1988-07-05 | ||
US08/215,220 US5498463A (en) | 1994-03-21 | 1994-03-21 | Polyethylene meltblown fabric with barrier properties |
Publications (2)
Publication Number | Publication Date |
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CA2130246A1 CA2130246A1 (en) | 1995-09-22 |
CA2130246C true CA2130246C (en) | 2004-02-10 |
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Application Number | Title | Priority Date | Filing Date |
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CA002130246A Expired - Fee Related CA2130246C (en) | 1994-03-21 | 1994-08-16 | Polyethylene meltblown fabric with barrier properties |
Country Status (6)
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US (1) | US5498463A (en) |
EP (1) | EP0674035A3 (en) |
JP (1) | JPH07300754A (en) |
KR (1) | KR100357671B1 (en) |
AU (1) | AU687980B2 (en) |
CA (1) | CA2130246C (en) |
Families Citing this family (67)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5652051A (en) * | 1995-02-27 | 1997-07-29 | Kimberly-Clark Worldwide, Inc. | Nonwoven fabric from polymers containing particular types of copolymers and having an aesthetically pleasing hand |
US5597647A (en) * | 1995-04-20 | 1997-01-28 | Kimberly-Clark Corporation | Nonwoven protective laminate |
US5804512A (en) * | 1995-06-07 | 1998-09-08 | Bba Nonwovens Simpsonville, Inc. | Nonwoven laminate fabrics and processes of making same |
US5662978A (en) * | 1995-09-01 | 1997-09-02 | Kimberly-Clark Worldwide, Inc. | Protective cover fabric including nonwovens |
US5709735A (en) * | 1995-10-20 | 1998-01-20 | Kimberly-Clark Worldwide, Inc. | High stiffness nonwoven filter medium |
JP4068171B2 (en) * | 1995-11-21 | 2008-03-26 | チッソ株式会社 | Laminated nonwoven fabric and method for producing the same |
US5616408A (en) * | 1995-12-22 | 1997-04-01 | Fiberweb North America, Inc. | Meltblown polyethylene fabrics and processes of making same |
US6103647A (en) * | 1996-03-14 | 2000-08-15 | Kimberly-Clark Worldwide, Inc. | Nonwoven fabric laminate with good conformability |
US20040097158A1 (en) * | 1996-06-07 | 2004-05-20 | Rudisill Edgar N. | Nonwoven fibrous sheet structures |
US5885909A (en) * | 1996-06-07 | 1999-03-23 | E. I. Du Pont De Nemours And Company | Low or sub-denier nonwoven fibrous structures |
US5843056A (en) | 1996-06-21 | 1998-12-01 | Kimberly-Clark Worldwide, Inc. | Absorbent article having a composite breathable backsheet |
US6028018A (en) * | 1996-07-24 | 2000-02-22 | Kimberly-Clark Worldwide, Inc. | Wet wipes with improved softness |
EP0957873B1 (en) * | 1996-12-20 | 2003-02-19 | Kimberly-Clark Worldwide, Inc. | Absorbent articles having reduced outer cover dampness |
US6015764A (en) | 1996-12-27 | 2000-01-18 | Kimberly-Clark Worldwide, Inc. | Microporous elastomeric film/nonwoven breathable laminate and method for making the same |
US6111163A (en) | 1996-12-27 | 2000-08-29 | Kimberly-Clark Worldwide, Inc. | Elastomeric film and method for making the same |
US6105578A (en) * | 1997-02-27 | 2000-08-22 | Kimberly-Clark Worldwide, Inc. | Equipment drape for use with an interventional magnetic resonance imaging device |
US5883028A (en) * | 1997-05-30 | 1999-03-16 | Kimberly-Clark Worldwide, Inc. | Breathable elastic film/nonwoven laminate |
US5932497A (en) * | 1997-09-15 | 1999-08-03 | Kimberly-Clark Worldwide, Inc. | Breathable elastic film and laminate |
EP1035815B1 (en) * | 1997-11-10 | 2004-02-25 | The Procter & Gamble Company | Disposable absorbent article having improved soft barrier cuff |
US6420627B1 (en) | 1997-11-10 | 2002-07-16 | The Procter & Gamble Company | Disposable absorbent article having improved soft barrier cuff |
US5879620A (en) * | 1997-11-13 | 1999-03-09 | Kimberly-Clark Worldwide, Inc. | Sterilization wrap and procedures |
WO1999028544A1 (en) * | 1997-12-04 | 1999-06-10 | Mitsui Chemicals, Inc. | Flexible laminate of nonwoven fabrics |
AU3653999A (en) | 1998-04-20 | 1999-11-08 | Bba Nonwovens Simpsonville, Inc. | Nonwoven fabric having both uv stability and flame retardancy and related methodfor its manufacture |
TW438673B (en) | 1998-05-01 | 2001-06-07 | Dow Chemical Co | Method of making a breathable, barrier meltblown nonwoven |
USH2086H1 (en) | 1998-08-31 | 2003-10-07 | Kimberly-Clark Worldwide | Fine particle liquid filtration media |
DE19927785C2 (en) * | 1999-06-18 | 2003-02-20 | Sandler Ag | Textile composite with high textile softness and improved layer adhesion |
ES2323164T5 (en) | 2000-09-15 | 2016-06-14 | Suominen Corporation | Disposable non-woven cleaning cloth and manufacturing procedure |
US6499982B2 (en) * | 2000-12-28 | 2002-12-31 | Nordson Corporation | Air management system for the manufacture of nonwoven webs and laminates |
US6657009B2 (en) | 2000-12-29 | 2003-12-02 | Kimberly-Clark Worldwide, Inc. | Hot-melt adhesive having improved bonding strength |
US6946413B2 (en) * | 2000-12-29 | 2005-09-20 | Kimberly-Clark Worldwide, Inc. | Composite material with cloth-like feel |
US6872784B2 (en) | 2000-12-29 | 2005-03-29 | Kimberly-Clark Worldwide, Inc. | Modified rubber-based adhesives |
US6774069B2 (en) | 2000-12-29 | 2004-08-10 | Kimberly-Clark Worldwide, Inc. | Hot-melt adhesive for non-woven elastic composite bonding |
US20020123538A1 (en) * | 2000-12-29 | 2002-09-05 | Peiguang Zhou | Hot-melt adhesive based on blend of amorphous and crystalline polymers for multilayer bonding |
US20020132543A1 (en) * | 2001-01-03 | 2002-09-19 | Baer David J. | Stretchable composite sheet for adding softness and texture |
US20020164446A1 (en) | 2001-01-17 | 2002-11-07 | Zhiming Zhou | Pressure sensitive adhesives with a fibrous reinforcing material |
US7078582B2 (en) | 2001-01-17 | 2006-07-18 | 3M Innovative Properties Company | Stretch removable adhesive articles and methods |
US6994904B2 (en) | 2001-05-02 | 2006-02-07 | 3M Innovative Properties Company | Pressure sensitive adhesive fibers with a reinforcing material |
US6894204B2 (en) | 2001-05-02 | 2005-05-17 | 3M Innovative Properties Company | Tapered stretch removable adhesive articles and methods |
US7176150B2 (en) * | 2001-10-09 | 2007-02-13 | Kimberly-Clark Worldwide, Inc. | Internally tufted laminates |
US6799957B2 (en) * | 2002-02-07 | 2004-10-05 | Nordson Corporation | Forming system for the manufacture of thermoplastic nonwoven webs and laminates |
KR100549140B1 (en) | 2002-03-26 | 2006-02-03 | 이 아이 듀폰 디 네모아 앤드 캄파니 | A electro-blown spinning process of preparing for the nanofiber web |
US20040116018A1 (en) * | 2002-12-17 | 2004-06-17 | Kimberly-Clark Worldwide, Inc. | Method of making fibers, nonwoven fabrics, porous films and foams that include skin treatment additives |
US20050133145A1 (en) * | 2003-12-22 | 2005-06-23 | Kimberly-Clark Worldwide, Inc. | Laminated absorbent product with ultrasonic bond |
US20050136224A1 (en) * | 2003-12-22 | 2005-06-23 | Kimberly-Clark Worldwide, Inc. | Ultrasonic bonding and embossing of an absorbent product |
US7955710B2 (en) * | 2003-12-22 | 2011-06-07 | Kimberly-Clark Worldwide, Inc. | Ultrasonic bonding of dissimilar materials |
US20050266229A1 (en) * | 2004-05-26 | 2005-12-01 | Richard Porticos | Nonwoven with attached foam particles |
US7585451B2 (en) * | 2004-12-27 | 2009-09-08 | E.I. Du Pont De Nemours And Company | Electroblowing web formation process |
US8808608B2 (en) * | 2004-12-27 | 2014-08-19 | E I Du Pont De Nemours And Company | Electroblowing web formation process |
DE102006013170A1 (en) * | 2006-03-22 | 2007-09-27 | Irema-Filter Gmbh | Foldable nonwoven material useful as air filter element in motor vehicle, comprises form stabilized thicker fiber carrier material and thinner fibers determining the filtering effect |
DE102006014236A1 (en) | 2006-03-28 | 2007-10-04 | Irema-Filter Gmbh | Fleece material used as a pleated air filter in a motor vehicle comprises thinner fibers homogeneously incorporated into thicker fibers |
US10041188B2 (en) * | 2006-04-18 | 2018-08-07 | Hills, Inc. | Method and apparatus for production of meltblown nanofibers |
US20090071114A1 (en) * | 2007-03-05 | 2009-03-19 | Alan Smithies | Gas turbine inlet air filtration filter element |
DE102010052155A1 (en) | 2010-11-22 | 2012-05-24 | Irema-Filter Gmbh | Air filter medium with two mechanisms of action |
US10245537B2 (en) | 2012-05-07 | 2019-04-02 | 3M Innovative Properties Company | Molded respirator having outer cover web joined to mesh |
DE102013008402A1 (en) | 2013-05-16 | 2014-11-20 | Irema-Filter Gmbh | Nonwoven fabric and process for producing the same |
CN110022800A (en) | 2016-12-02 | 2019-07-16 | 3M创新有限公司 | Muscle or joint support product with band |
CN110022801A (en) | 2016-12-02 | 2019-07-16 | 3M创新有限公司 | Muscle or joint support product with protrusion |
CN110049749A (en) | 2016-12-02 | 2019-07-23 | 3M创新有限公司 | Muscle or joint support product |
BR112019019236B1 (en) | 2017-03-17 | 2024-02-06 | Dow Global Technologies Llc | ETHYLENE/ALPHA-OLEPHIN INTERPOLYMER SUITABLE FOR USE IN FIBERS AND NON-WOVEN FABRICS, MELT-BLOWN NON-WOVEN FABRIC AND COMPOSITE STRUCTURE |
US10322562B2 (en) | 2017-07-27 | 2019-06-18 | Hollingsworth & Vose Company | Medical protective clothing materials |
US10480110B2 (en) | 2017-10-09 | 2019-11-19 | The Clorox Company | Melamine wipes and methods of manufacture |
CN111556909B (en) | 2017-11-22 | 2024-04-09 | 挤压集团公司 | Meltblowing die tip assembly and method |
WO2019222600A1 (en) * | 2018-05-17 | 2019-11-21 | Pfnonwovens, Llc | Multilayered nonwoven fabrics and method of making the same |
AR119400A1 (en) | 2019-07-26 | 2021-12-15 | Dow Global Technologies Llc | BI-COMPOSITE FIBERS, MELT-BLOWN NON-WOVEN FABRICS, AND COMPOSITES OF THESE |
WO2021101751A1 (en) * | 2019-11-18 | 2021-05-27 | Berry Global, Inc. | Nonwoven fabric having high thermal resistance and barrier properties |
CN111455473A (en) * | 2020-04-14 | 2020-07-28 | 江阴市合助机械科技有限公司 | Spinneret plate and processing method thereof |
CN113550070B (en) * | 2021-07-27 | 2023-07-04 | 杭州凯源过滤器材有限公司 | Melt-blown cloth forming device |
Family Cites Families (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3338992A (en) * | 1959-12-15 | 1967-08-29 | Du Pont | Process for forming non-woven filamentary structures from fiber-forming synthetic organic polymers |
US3502763A (en) * | 1962-02-03 | 1970-03-24 | Freudenberg Carl Kg | Process of producing non-woven fabric fleece |
US3341394A (en) * | 1966-12-21 | 1967-09-12 | Du Pont | Sheets of randomly distributed continuous filaments |
US3542615A (en) * | 1967-06-16 | 1970-11-24 | Monsanto Co | Process for producing a nylon non-woven fabric |
US3849241A (en) * | 1968-12-23 | 1974-11-19 | Exxon Research Engineering Co | Non-woven mats by melt blowing |
US3978185A (en) * | 1968-12-23 | 1976-08-31 | Exxon Research And Engineering Company | Melt blowing process |
DE2048006B2 (en) * | 1969-10-01 | 1980-10-30 | Asahi Kasei Kogyo K.K., Osaka (Japan) | Method and device for producing a wide nonwoven web |
DE1950669C3 (en) * | 1969-10-08 | 1982-05-13 | Metallgesellschaft Ag, 6000 Frankfurt | Process for the manufacture of nonwovens |
CA948388A (en) * | 1970-02-27 | 1974-06-04 | Paul B. Hansen | Pattern bonded continuous filament web |
GB1453447A (en) * | 1972-09-06 | 1976-10-20 | Kimberly Clark Co | Nonwoven thermoplastic fabric |
US3909009A (en) * | 1974-01-28 | 1975-09-30 | Astatic Corp | Tone arm and phonograph pickup assemblies |
US4275105A (en) * | 1978-06-16 | 1981-06-23 | The Buckeye Cellulose Corporation | Stabilized rayon web and structures made therefrom |
US4196245A (en) * | 1978-06-16 | 1980-04-01 | Buckeye Cellulos Corporation | Composite nonwoven fabric comprising adjacent microfine fibers in layers |
US4298649A (en) * | 1980-01-07 | 1981-11-03 | Kimberly-Clark Corporation | Nonwoven disposable wiper |
US4340563A (en) * | 1980-05-05 | 1982-07-20 | Kimberly-Clark Corporation | Method for forming nonwoven webs |
US4436780A (en) * | 1982-09-02 | 1984-03-13 | Kimberly-Clark Corporation | Nonwoven wiper laminate |
US4586606B1 (en) * | 1983-10-28 | 1998-01-06 | Int Paper Co | Nonwoven fabric |
US4880691A (en) * | 1984-02-17 | 1989-11-14 | The Dow Chemical Company | Fine denier fibers of olefin polymers |
US4830907A (en) * | 1984-11-16 | 1989-05-16 | The Dow Chemical Company | Fine denier fibers of olefin polymers |
US4909975A (en) * | 1984-02-17 | 1990-03-20 | The Dow Chemical Company | Fine denier fibers of olefin polymers |
US4595629A (en) * | 1984-03-09 | 1986-06-17 | Chicopee | Water impervious materials |
US4508113A (en) * | 1984-03-09 | 1985-04-02 | Chicopee | Microfine fiber laminate |
US4555811A (en) * | 1984-06-13 | 1985-12-03 | Chicopee | Extensible microfine fiber laminate |
US4554207A (en) * | 1984-12-10 | 1985-11-19 | E. I. Du Pont De Nemours And Company | Stretched-and-bonded polyethylene plexifilamentary nonwoven sheet |
US4758239A (en) * | 1986-10-31 | 1988-07-19 | Kimberly-Clark Corporation | Breathable barrier |
US4766029A (en) * | 1987-01-23 | 1988-08-23 | Kimberly-Clark Corporation | Semi-permeable nonwoven laminate |
US4891957A (en) * | 1987-06-22 | 1990-01-09 | Kimberly-Clark Corporation | Stitchbonded material including elastomeric nonwoven fibrous web |
US4818597A (en) * | 1988-01-27 | 1989-04-04 | Kimberly-Clark Corporation | Health care laminate |
US4863785A (en) * | 1988-11-18 | 1989-09-05 | The James River Corporation | Nonwoven continuously-bonded trilaminate |
US5073436A (en) * | 1989-09-25 | 1991-12-17 | Amoco Corporation | Multi-layer composite nonwoven fabrics |
US5169706A (en) * | 1990-01-10 | 1992-12-08 | Kimberly-Clark Corporation | Low stress relaxation composite elastic material |
US5208098A (en) * | 1990-10-23 | 1993-05-04 | Amoco Corporation | Self-bonded nonwoven web and porous film composites |
US5149576A (en) * | 1990-11-26 | 1992-09-22 | Kimberly-Clark Corporation | Multilayer nonwoven laminiferous structure |
US5405682A (en) * | 1992-08-26 | 1995-04-11 | Kimberly Clark Corporation | Nonwoven fabric made with multicomponent polymeric strands including a blend of polyolefin and elastomeric thermoplastic material |
-
1994
- 1994-03-21 US US08/215,220 patent/US5498463A/en not_active Expired - Lifetime
- 1994-08-16 CA CA002130246A patent/CA2130246C/en not_active Expired - Fee Related
-
1995
- 1995-02-24 EP EP95102693A patent/EP0674035A3/en not_active Withdrawn
- 1995-03-20 AU AU14950/95A patent/AU687980B2/en not_active Ceased
- 1995-03-20 KR KR1019950005737A patent/KR100357671B1/en not_active IP Right Cessation
- 1995-03-20 JP JP7060661A patent/JPH07300754A/en active Pending
Also Published As
Publication number | Publication date |
---|---|
EP0674035A2 (en) | 1995-09-27 |
AU687980B2 (en) | 1998-03-05 |
AU1495095A (en) | 1995-09-28 |
KR100357671B1 (en) | 2003-01-24 |
CA2130246A1 (en) | 1995-09-22 |
EP0674035A3 (en) | 1999-04-21 |
KR950032793A (en) | 1995-12-22 |
US5498463A (en) | 1996-03-12 |
JPH07300754A (en) | 1995-11-14 |
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Legal Events
Date | Code | Title | Description |
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EEER | Examination request | ||
MKLA | Lapsed |