US5486411A
Expired / Lapsed
US
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Electrically charged, consolidated non-woven webs
Assignee: University of Tennessee Research Foundation
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Filing: 1992-09-28
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Granted: 1996-01-23
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Expires: 2012-09-28
Abstract
Abstract A consolidated non-woven web made by post-treating a precursor nonwoven web including consolidating the web laterally by drawing, thereby reducing the maximum pore size measure of the web and improving the filtration efficiency of the web, and subjecting the consolidated web to an electrostatic field to further enhance filtration efficiency.
Inventors
- 👤 Charles B. Hassenboehler, Jr.
- 👤 Larry B. Wadsworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:22
CPC Classifications
D; D06; D06C; D06C3/00; B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D39/163; B03; B03C; B03C3/00; B03C3/28; B29; B29C; B29C55/00; B29C55/02; B29C55/04; B29C55/06; B32; B32B; B32B27/00; B32B27/12; B32B5/00; B32B5/02; B32B5/22; B32B5/24; B32B5/26; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/559; D04H1/56; D04H13/00; D04H3/00; D04H3/08; D04H3/14; B01D2239/00; B01D2239/04; B01D2239/0471; B01D2239/0492; B01D2239/06; B01D2239/0604; B01D2239/0622; B01D2239/0627; B01D2239/065; B01D2239/0668; B01D2239/0672; B01D2239/0681; B01D2239/12; B01D2239/1233; D06C3/06; Y; Y10; Y10S; Y10S428/00; Y10S428/903; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249981; Y10T442/00; Y10T442/60; Y10T442/601; Y10T442/608; Y10T442/614; Y10T442/62; Y10T442/659; Y10T442/66; Y10T442/68; Y10T442/696
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
154 words
A post-electrostatically charged, consolidated nonwoven web of improved filtration performance which is consolidated and elastic in the cross-direction, which consolidated web is made by drawing and heat setting a precursor nonwoven web of nonelastomeric, thermoplastic fibers, wherein the consolidated web has a reduced average pore size and reduced pore size distribution with respect to the precursor web, the web comprising a planar layer of randomly organized, nonelastomeric thermoplastic fibers bonded to each other, a majority of fibers being aligned generally in the direction of draw and a minority of fibers disposed in a cross-direction transverse to the direction of the draw, the consolidated web having a maximum pore size of less than 80% of that of the precursor web, wherein the average pore size reduction which results from lateral contraction of the web during drawing is not accompanied by a significant average fiber diameter reduction of the fibers which are aligned in the direction.
Claim 2
Dependent Claim
154 words
A post-electrostatically charged, consolidated nonwoven web of improved filtration performance which is consolidated and elastic in the cross-direction, which consolidated web is made by drawing and heat setting a precursor nonwoven web of nonelastomeric, thermoplastic fibers, wherein the consolidated web has a reduced average pore size and reduced pore size distribution with respect to the precursor web, the web comprising a planar layer of randomly organized, nonelastomeric thermoplastic fibers bonded to each other, a majority of fibers being aligned generally in the direction of draw and a minority of fibers disposed in a cross-direction transverse to the direction of the draw, the consolidated web having a maximum pore size of less than 80% of that of the precursor web, wherein the average pore size reduction which results from lateral contraction of the web during drawing is not accompanied by a significant average fiber diameter reduction of the fibers which are aligned in the direction.
Claim 3
Dependent Claim
21 words
The electrostatically charged, consolidated nonwoven web of claim 1 wherein the precursor web is a composite comprising at least two layers.
Claim 4
Dependent Claim
21 words
The electrostatically charged, consolidated nonwoven web of claim 1 wherein the precursor web is a composite comprising at least three layers.
Claim 5
Dependent Claim
15 words
The electrostatically charged, consolidated nonwoven web of claim 1 wherein the precursor web is meltblown.
Claim 6
Dependent Claim
24 words
The electrostatically charged, consolidated nonwoven web of claim 3 wherein the three layers are a spunbond web, a meltblown web and a spunbond web.
Claim 7
Dependent Claim
28 words
The electrostatically charged, consolidated nonwoven web of claim 1 wherein the consolidated web has a average pore size of less than 80% than that of the precursor web.
Claim 8
Dependent Claim
25 words
The electrostatically charged, consolidated nonwoven web of claim 1 wherein the thermoplastic fibers of the precursor non-consolidated web have a crystallinity of at least 30%.
Claim 9
Dependent Claim
28 words
The electrostatically charged consolidated nonwoven web of claim 1 wherein the fibers are at least partially coated with a surfactant, thereby increasing the water wettability of the web.
Claim 10
Dependent Claim
17 words
A laminate comprising the consolidated web of claim 1 and a polymeric substrate bonded to said web.
Claim 11
Dependent Claim
13 words
The nonwoven laminate of claim 9 wherein the substrate is an elastomeric web.
Claim 12
Dependent Claim
12 words
The nonwoven laminate of claim 9 wherein the substrate is a film.
Claim 13
Dependent Claim
25 words
The nonwoven laminate of claim 9 wherein the substrate is a textile that limits the cross-direction extensibility of the laminate to less than 100% strain.
Claim 14
Dependent Claim
18 words
The electrostatically charged, consolidated nonwoven web of claim 3 which comprises a lamination of individual nonwoven, consolidated webs.
Claim 15
Dependent Claim
13 words
The electrostatically charged, consolidated nonwoven web of claim 1 which is a filter.
Claim 16
Dependent Claim
38 words
The electrostatically charged consolidated web of claim 1 wherein the maximum pore size of the consolidated web is reduced by at least 20% and the pore size distribution by at least 20% with respect to the precursor web.
Claim 17
Dependent Claim
22 words
The electrostatically charged consolidated web of claim 1 wherein the elongation at break at the precursor web is between 5 to 20%.
Claim 18
Dependent Claim
34 words
The electrostatically charged consolidated web of claim 1 wherein the non-elastomeric fibers of the precursor web do not have the ability to stretch at least twice their original length and retract at room temperature.
Claim 19
Dependent Claim
19 words
The electrostatically charged consolidated web of claim 1 wherein the crystallinity of the precursor fibers is at least 30%.
Claim 20
Dependent Claim
26 words
The electrostatically charged consolidated web of claim 18 wherein the crystallinity of the fibers of the precursor web is in the range of 30 to 70%.
Claim 21
Dependent Claim
30 words
The electrostatically charged consolidated web of claim 1 wherein the consolidated web has an elasticity in the cross-direction of at least 70% recovery from a 50% elongation in the cross-direction.
Claim 22
Dependent Claim
32 words
The post-electrostatically charged consolidated web of claim 1 wherein the room temperature elongation (strain) of the precursor web at break is between 2 to 40%, based On test method ASTM D 1117-717.
Claim 23
Dependent Claim
43 words
The post-electrostatically charged, consolidated nonwoven web of claim 1 wherein the nonwoven precursor web is a meltblown web having an average fiber diameter of 0.5 to 8 microns and having an elongation at break of less than 30% based on ASTM D 5035-90.
Claim 24
Dependent Claim
26 words
The post-electrically charged, consolidated nonwoven web of claim 5 wherein the precursor nonwoven web has a breaking elongation less than 40% based on ASTM D 5035-90.
Claim 25
Dependent Claim
15 words
The of claim 1 wherein the meltblown precursor web has randomly distributed throughout fiber-fiber bonding.
Claim 26
Dependent Claim
33 words
The post-electrically charged, consolidated nonwoven web of claim 2 wherein the thermoplastic is selected from the group consisting of polyesters, polyamides, cellulose triacetate, cellulose diacetate, poly-4-methylpenetene-1, polyphenelene sulfide, liquid crystal polymers and fluropolymers.
Claim 27
Dependent Claim
37 words
The post-electrically charged, consolidated nonwoven web of claim 1 wherein the precursor nonwoven web is a spun-bond web having fibers of from 7 to 50 micron average diameter and having spaced apart bonds distributed through the web.
Claim 28
Dependent Claim
43 words
The post-electrically charged, consolidated nonwoven web of claim 1 wherein the precursor nonwoven web is made of a laminate of at least two distinct nonwoven webs, each web made of randomly collected nonelastomeric thermoplastic fibers and each web has distributed throughout fiber-fiber bonding.
Claim 29
Dependent Claim
36 words
The post-electrically charged, consolidated nonwoven web of claim 1 wherein the precursor web is a composite comprising a spunbond layer/a meltblown layer/and a spunbond layer, wherein the layers are thermally bonded together at spaced apart locations.
Claim 30
Dependent Claim
31 words
The post-electrically charged, nonwoven web of claim 1 wherein the precursor web is composed of nonelastomeric thermoplastic meltblown fibers randomly bonded and having an average diameter of 0.5 to 8 microns.
Claim 31
Dependent Claim
25 words
The consolidated elecrostatically charged, nonwoven web of claim 29 wherein the consolidated web has a mean flow pore size of between 3 to 40 microns.
Claim 32
Dependent Claim
32 words
The electrostatically charged consolidated web of claim 1 wherein the precursor web is drawn at an elevated temperature and then subjected to the electrostatic charge prior to cooling below about 90° C.
Claim 33
Dependent Claim
39 words
The post-electrostatically charged consolidated web of claim 31 wherein the temperature to which the web is exposed during drawing is greater than the softening point but at least 10° F. less than the melting temperature of the thermoplastic fibers.
Claim 34
Dependent Claim
27 words
The post-electrostatically charged consolidated web of claim 31 wherein the web is electrostatically charged when it has cooled to within a temperature of 90° and 130° C.
Claim 35
Dependent Claim
24 words
The post-electrostatically charged consolidated nonwoven web of claim 31 wherein the precursor web is drawn at a temperature in the range of 165°-425° F.
Claim 36
Dependent Claim
24 words
The post-electrostatically charged consolidated nonwoven web of claim 33 wherein the precursor web is drawn at a temperature in the range of 250°-350° F.
Claim 37
Dependent Claim
24 words
The post-electrostatically charged consolidated nonwoven web of claim 33 wherein the precursor web is drawn at a temperature in the range of 275°-300° F.
Claim 38
Dependent Claim
142 words
A post-electrostatically charged, consolidated nonwoven web of improved filtration performance which is consolidated and elastic in the cross-direction, which consolidated web is made from a precursor nonwoven web of nonelastomeric heat set, thermoplastic polyolefin fibers having a crystallinity of at least 30%, said consolidated web having reduced average pore size and reduce pore size distribution with respect to the precursor web, the consolidated web comprising a planar layer of randomly organized, nonelastomeric thermoplastic fibers bonded to each other, a majority of fibers being aligned generally in the direction of draw and a minority of fibers disposed in a cross-direction transverse to the direction of the draw, the consolidated web having a maximum pore size of less than 80% of that of the precursor web and an elasticity in the cross-direction of at least 70% recovery from a 50% elongation in the cross-direction.
Claim 39
Dependent Claim
142 words
A post-electrostatically charged, consolidated nonwoven web of improved filtration performance which is consolidated and elastic in the cross-direction, which consolidated web is made from a precursor nonwoven web of nonelastomeric heat set, thermoplastic polyolefin fibers having a crystallinity of at least 30%, said consolidated web having reduced average pore size and reduce pore size distribution with respect to the precursor web, the consolidated web comprising a planar layer of randomly organized, nonelastomeric thermoplastic fibers bonded to each other, a majority of fibers being aligned generally in the direction of draw and a minority of fibers disposed in a cross-direction transverse to the direction of the draw, the consolidated web having a maximum pore size of less than 80% of that of the precursor web and an elasticity in the cross-direction of at least 70% recovery from a 50% elongation in the cross-direction.
Claim 40
Dependent Claim
21 words
The electrostatically charged consolidated web of claim 37 wherein the polyolefin fibers are selected from the group of polypropylene and polyethylene.
Claim 41
Dependent Claim
14 words
The electrostatically charged, consolidated web of claim 38 wherein the fibers are polypropylene fibers.
Claim 42
Dependent Claim
20 words
The electrostatically charged consolidated web of claim 37 wherein the precursor web is of polyolefins and are meltblown or spunbond.
Claim 43
Dependent Claim
108 words
An electrostatically charged, consolidated nonwoven web made from a precursor nonwoven web, said precursor comprising a lamination of individual nonwoven webs having nonelastomeric fibers, said consolidated web having been heated, uniaxially drawn, heat set before coling to an electrostatic field, wherein a majority of the fibers are consolidated and aligned generally in the direction of draw and a minority of the fibers are disposed in a cross-direction transverse to the direction of draw, said web having a maximum pore size of less than 80% that of the precursor web and an elasticity in the cross-direction defined by at least 70% recovery from a 50% elongation in the cross-direction.
Claim 44
Dependent Claim
108 words
An electrostatically charged, consolidated nonwoven web made from a precursor nonwoven web, said precursor comprising a lamination of individual nonwoven webs having nonelastomeric fibers, said consolidated web having been heated, uniaxially drawn, heat set before coling to an electrostatic field, wherein a majority of the fibers are consolidated and aligned generally in the direction of draw and a minority of the fibers are disposed in a cross-direction transverse to the direction of draw, said web having a maximum pore size of less than 80% that of the precursor web and an elasticity in the cross-direction defined by at least 70% recovery from a 50% elongation in the cross-direction.
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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) | 1999-01-22 | 1999-07-24 | 2000-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-22 | 2003-07-24 | 2004-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-22 | 2007-07-24 | 2008-01-23 | $7700.00 | Window Closed / Lapsed |