US5554435A
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US
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Textile structures, and their preparation
Assignee: Fibervisions Lp
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Filing: 1994-03-18
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Granted: 1996-09-10
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Expires: 2014-03-18
Abstract
Abstract Nonwoven structures, prepared from meltblown microfibers, and fibers having heterogeneous melt viscosity. The structures can be in the form of composite nonwoven fabrics, made from alternating layers of the indicated meltblown and heterogeneous fibers; the melt flow rate, of the surface of the heterogeneous fibers, can be one third or more of the meltblown fibers' melt flow rate. The composite nonwoven fabrics have excellent barrier properties, and are useful as sterilization wraps, and for other medical, industrial, and hygiene applications.
Inventors
- 👤 Rakesh K. Gupta
- 👤 Richard J. Legare
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:57
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/558; D04H1/42; D04H1/4282; D04H1/4291; D04H1/4374; D04H1/4382; D04H1/43825; D04H1/43828; D04H1/43838; D04H1/541; D04H1/559; D04H1/56; D04H3/00; D04H3/08; D04H3/14; Y; Y10; Y10T; Y10T442/00; Y10T442/60; Y10T442/608; Y10T442/614; Y10T442/621; Y10T442/637; Y10T442/641; Y10T442/659; Y10T442/66
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
42 words
A nonwoven structure comprising first fibers and second fibers: the first fibers comprising meltblown microfibers; and the second fibers consisting essentially of a single polymer or polymer alloy, and having nonuniform melt viscosity and a substantially constant melting point across their cross-sections.
Claim 2
Dependent Claim
42 words
A nonwoven structure comprising first fibers and second fibers: the first fibers comprising meltblown microfibers; and the second fibers consisting essentially of a single polymer or polymer alloy, and having nonuniform melt viscosity and a substantially constant melting point across their cross-sections.
Claim 3
Dependent Claim
33 words
The nonwoven structure of claim 1, comprising a composite nonwoven structure, the composite nonwoven structure comprising at least one layer of the first fibers and at least one layer of the second fibers.
Claim 4
Dependent Claim
35 words
The composite nonwoven structure of claim 2, wherein the at least one layer of the first fibers and the at least one layer of the second fibers are positioned in alternating surface to surface relationship.
Claim 5
Dependent Claim
38 words
The composite nonwoven structure of claim 3, wherein the second fibers comprise a member selected from the group consisting of: monocomponent fibers comprising thermally oxidized surfaces; and multicomponent fibers comprising a core and at least one concentric layer.
Claim 6
Dependent Claim
35 words
The composite nonwoven structure of claim 4, wherein the second fibers are differentially stainable by RuO 4 , the surface of the second fibers demonstrating a darker stain than interior regions of the second fibers.
Claim 7
Dependent Claim
18 words
The composite nonwoven structure of claim 5, wherein the second fibers are monocomponent fibers comprising thermally oxidized surfaces.
Claim 8
Dependent Claim
34 words
The composite nonwoven structure of claim 4, wherein the melt flow rate, of the surface of the second fibers, is at least about one third of the melt flow rate of the first fibers.
Claim 9
Dependent Claim
45 words
The composite nonwoven structure of claim 7, wherein the first fibers comprise a first polymer and the second fibers consist essentially of a second polymer, the first polymer and the second polymer being selected from the group consisting of similar polymers, and substantially identical polymers.
Claim 10
Dependent Claim
17 words
The composite nonwoven structure of claim 8, wherein the first fibers and the second fibers are hydrophobic.
Claim 11
Dependent Claim
20 words
The composite nonwoven structure of claim 8, wherein each of the first polymer and the second polymer is a polyolefin.
Claim 12
Dependent Claim
12 words
The composite nonwoven structure of claim 10, wherein the polyolefin is polypropylene.
Claim 13
Dependent Claim
53 words
The composite nonwoven structure of claim 11, wherein the melt flow rate of the first fibers is about 800-1200 decigrams/minute, measured according to ASTM D1238L-82, Condition FR-230/2.16, and the melt flow rate, of the surface of the second fibers, is at least about 265 decigrams/minute, measured by conversion from the Intrinsic Viscosity value.
Claim 14
Dependent Claim
33 words
The composite nonwoven structure of claim 12, wherein the melt flow rate, of the surface of the second fibers, is at least about 800 decigrams/minute, measured by conversion from the Intrinsic Viscosity value.
Claim 15
Dependent Claim
53 words
A nonwoven structure comprising first fibers and second fibers: the first fibers comprising meltblown microfibers; and the second fibers having nonuniform melt viscosity across their cross-sections; wherein the melt flow rate, of the surface of the second fibers, is at least about one third of the melt flow rate of the first fibers.
Claim 16
Dependent Claim
53 words
A nonwoven structure comprising first fibers and second fibers: the first fibers comprising meltblown microfibers; and the second fibers having nonuniform melt viscosity across their cross-sections; wherein the melt flow rate, of the surface of the second fibers, is at least about one third of the melt flow rate of the first fibers.
Claim 17
Dependent Claim
33 words
The nonwoven structure of claim 14, comprising a composite nonwoven structure, the composite nonwoven structure comprising at least one layer of the first fibers and at least one layer of the second fibers.
Claim 18
Dependent Claim
35 words
The composite nonwoven structure of claim 15, wherein the at least one layer of the first fibers and the at least one layer of the second fibers are positioned in alternating surface to surface relationship.
Claim 19
Dependent Claim
23 words
The composite nonwoven structure of claim 16, wherein the second fibers comprise multicomponent fibers comprising a core and at least one concentric layer.
Claim 20
Dependent Claim
46 words
The composite nonwoven structure of claim 16, wherein the first fibers comprise a first polymer and the surface of the second fibers comprise a second polymer, the first polymer and the second polymer being selected from the group consisting of similar polymers, and substantially identical polymers.
Claim 21
Dependent Claim
20 words
The composite nonwoven structure of claim 18, wherein the first fibers and the surface of the second fibers are hydrophobic.
Claim 22
Dependent Claim
20 words
The composite nonwoven structure of claim 18, wherein the first fibers and the surface of the second fibers comprise polyolefin.
Claim 23
Dependent Claim
12 words
The composite nonwoven structure of claim 20, wherein the polyolefin comprises polypropylene.
Claim 24
Dependent Claim
53 words
The composite nonwoven structure of claim 21, wherein the melt flow rate of the first fibers is about 800-1200 decigrams/minute, measured according to ASTM D1238L-82, Condition FR-230/2.16, and the melt flow rate, of the surface of the second fibers, is at least about 265 decigrams/minute, measured by conversion from the Intrinsic Viscosity value.
Claim 25
Dependent Claim
33 words
The composite nonwoven structure of claim 22, wherein the melt flow rate, of the surface of the second fibers, is at least about 800 decigrams/minute, measured by conversion from the Intrinsic Viscosity value.
Claim 26
Independent Claim
86 words
A method of preparing a composite nonwoven structure, comprising at least one layer of first fibers and at least one layer of second fibers, the first fibers comprising meltblown microfibers; and the second fibers consisting essentially of a single polymer or polymer alloy, and having nonuniform melt viscosity and a substantially constant melting point across their cross-sections; the method comprising a bonding step, of thermally bonding the at least one layer of first fibers and the at least one layer of second fibers to one another.
Claim 27
Independent Claim
86 words
A method of preparing a composite nonwoven structure, comprising at least one layer of first fibers and at least one layer of second fibers, the first fibers comprising meltblown microfibers; and the second fibers consisting essentially of a single polymer or polymer alloy, and having nonuniform melt viscosity and a substantially constant melting point across their cross-sections; the method comprising a bonding step, of thermally bonding the at least one layer of first fibers and the at least one layer of second fibers to one another.
Claim 28
Dependent Claim
32 words
The method of claim 24, further comprising, prior to the bonding step, a preliminary bonding step, comprising thermally bonding carded staple fibers, to obtain the at least one layer of second fibers.
Claim 29
Dependent Claim
32 words
The method of claim 24, wherein the second fibers comprise spunbonded continuous filaments, the method further comprising, prior to the bonding step, preparation of the at least one layer of second fibers.
Claim 30
Dependent Claim
29 words
The method of claim 24, wherein the bonding step comprises calender bonding the at least one layer of first fibers and the at least one layer of second fibers.
Claim 31
Dependent Claim
15 words
The method of claim 24, wherein the first fibers and second fibers comprise polyolefin fibers.
Claim 32
Dependent Claim
10 words
The method of claim 28, wherein the polyolefin comprises polypropylene.
Claim 33
Dependent Claim
32 words
The method of claim 29, wherein the second fibers comprise spunbonded continuous filaments, the method further comprising, prior to the bonding step, preparation of the at least one layer of second fibers.
Claim 34
Independent Claim
95 words
A method of preparing a composite nonwoven structure, comprising at least one layer of first fibers and at least one layer of second fibers, the first fibers comprising meltblown microfibers; and the second fibers having nonuniform melt viscosity across their cross-sections, and having surfaces characterized by a melt flow rate which is at least about one third of the melt flow rate of the first fibers; the method comprising a bonding step, of thermally bonding the at least one layer of first fibers and the at least one layer of second fibers to one another.
Claim 35
Independent Claim
95 words
A method of preparing a composite nonwoven structure, comprising at least one layer of first fibers and at least one layer of second fibers, the first fibers comprising meltblown microfibers; and the second fibers having nonuniform melt viscosity across their cross-sections, and having surfaces characterized by a melt flow rate which is at least about one third of the melt flow rate of the first fibers; the method comprising a bonding step, of thermally bonding the at least one layer of first fibers and the at least one layer of second fibers to one another.
Claim 36
Dependent Claim
32 words
The method of claim 31, further comprising, prior to the bonding step, a preliminary bonding step, comprising thermally bonding carded staple fibers, to obtain the at least one layer of second fibers.
Claim 37
Dependent Claim
32 words
The method of claim 31, wherein the second fibers comprise spunbonded continuous filaments, the method further comprising, prior to the bonding step, preparation of the at least one layer of second fibers.
Claim 38
Dependent Claim
29 words
The method of claim 31, wherein the bonding step comprises calender bonding the at least one layer of first fibers and the at least one layer of second fibers.
Claim 39
Dependent Claim
15 words
The method of claim 31, wherein the first fibers and second fibers comprise polyolefin fibers.
Claim 40
Dependent Claim
10 words
The method of claim 35, wherein the polyolefin comprises polypropylene.
Claim 41
Dependent Claim
32 words
The method of claim 36, wherein the second fibers comprise spunbonded continuous filaments, the method further comprising, prior to the bonding step, preparation of the at least one layer of second fibers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-10 | 2000-03-11 | 2000-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-10 | 2004-03-11 | 2004-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-10 | 2008-03-11 | 2008-09-10 | $7700.00 | Window Closed / Lapsed |