Patent US5709735A successfully refreshed from Google Patents.
US5709735A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High stiffness nonwoven filter medium
Assignee: Kimberly Clark Worldwide Inc
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Filing: 1995-10-20
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Granted: 1998-01-20
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Expires: 2015-10-20
Abstract
Abstract A filter medium having high stiffness is provided. The filter is a nonwoven web of conjugate fibers which has a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80. The conjugate fibers may be polyolefin, more particularly polypropylene and polyethylene in a side-by-side configuration. The medium may be made into a filter by conventional means such as pleating. Such filters are useful in HVAC systems and transportation cabin air filtration.
Inventors
- 👤 David Grant Midkiff
- 👤 James Richard Neely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:42
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/52; B01D46/521; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D46/0001; B01D46/10; D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; F; F24; F24F; F24F8/00; F24F8/10; F24F8/108; B01D2239/00; B01D2239/02; B01D2239/0216; B01D2239/0225; B01D2239/0233; B01D2239/04; B01D2239/0435; B01D2239/06; B01D2239/0604; B01D2239/0622; B01D2239/0627; B01D2239/069; B01D2239/0695; B01D2239/12; B01D2239/1258; B01D2239/1291; B01D2279/00; B01D2279/50; Y; Y10; Y10S; Y10S55/00; Y10S55/05; Y10S55/39; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249962; Y10T428/249964
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
36 words
A filter medium comprising a nonwoven web of conjugate fibers having a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80.
Claim 2
Dependent Claim
36 words
A filter medium comprising a nonwoven web of conjugate fibers having a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80.
Claim 3
Dependent Claim
19 words
The filter medium of claim 1 which has a basis weight between about 68 gsm and about 340 gsm.
Claim 4
Dependent Claim
19 words
The filter medium of claim 1 wherein said fibers are comprised of polypropylene and polyethylene in a side-by-side configuration.
Claim 5
Dependent Claim
34 words
The filter medium of claim 1 wherein said filter medium has a first side and a second side and further wherein conjugate fibers adjacent said first side are bonded together at fiber crossover points.
Claim 6
Dependent Claim
25 words
The filter medium of claim 4 wherein said first side of said web has an increased stiffness relative to the second side of said web.
Claim 7
Dependent Claim
13 words
The filter medium of claim 1 wherein said fibers have an electric charge.
Claim 8
Dependent Claim
9 words
The filter medium of claim 6 which is pleated.
Claim 9
Dependent Claim
81 words
A filter medium comprising a nonwoven web of crimped polypropylene/polyethylene side-by-side conjugate fibers having a basis weight between about 68 gsm and about 340 gsm and having a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80, formed by a process wherein said web is subjected to hot air knife treatment, through-air bonding and electret treatment wherein said electret treatment imparts a charge to said fibers.
Claim 10
Dependent Claim
81 words
A filter medium comprising a nonwoven web of crimped polypropylene/polyethylene side-by-side conjugate fibers having a basis weight between about 68 gsm and about 340 gsm and having a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80, formed by a process wherein said web is subjected to hot air knife treatment, through-air bonding and electret treatment wherein said electret treatment imparts a charge to said fibers.
Claim 11
Dependent Claim
9 words
The filter medium of claim 8 which is pleated.
Claim 12
Dependent Claim
98 words
A pleated filter comprising a nonwoven web of crimped polypropylene/polyethylene side-by-side conjugate fibers having a basis weight between about 68 gsm and about 340 gsm, a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80, formed by a process wherein said web is subjected to hot air knife treatment immediately after formation, through-air bonding after said hot air knife treatment, electret treatment to impart a charge to said fibers after said through-air bonding, and wherein said web is pleated to form a filter.
Claim 13
Dependent Claim
98 words
A pleated filter comprising a nonwoven web of crimped polypropylene/polyethylene side-by-side conjugate fibers having a basis weight between about 68 gsm and about 340 gsm, a Frazier permeability above 200 CFM, an NaCl efficiency above 75 percent, a Gurley Stiffness above 700 mg, and a SEP value of above 80, formed by a process wherein said web is subjected to hot air knife treatment immediately after formation, through-air bonding after said hot air knife treatment, electret treatment to impart a charge to said fibers after said through-air bonding, and wherein said web is pleated to form a filter.
Claim 14
Dependent Claim
19 words
The filter medium of claim 1 wherein said nonwoven web is adapted to fit an HVAC air filtration system.
Claim 15
Dependent Claim
20 words
The filter medium of claim 1 wherein said nonwoven web is adapted to fit an transportation cabin air filtration system.
Claim 16
Dependent Claim
20 words
The filter medium of claim 1 wherein said nonwoven web is adapted to fit an automobile cabin air filtration system.
Claim 17
Dependent Claim
19 words
The filter medium of claim 9 wherein said nonwoven web is adapted to fit an HVAC air filtration system.
Claim 18
Dependent Claim
20 words
The filter medium of claim 9 wherein said nonwoven web is adapted to fit an transportation cabin air filtration system.
Claim 19
Dependent Claim
20 words
The filter medium of claim 9 wherein said nonwoven web is adapted to fit an automobile cabin air filtration system.
Claim 20
Dependent Claim
19 words
The filter medium of claim 10 wherein said nonwoven web is adapted to fit an HVAC air filtration system.
Claim 21
Dependent Claim
20 words
The filter medium of claim 10 wherein said nonwoven web is adapted to fit an transportation cabin air filtration system.
Claim 22
Dependent Claim
20 words
The filter medium of claim 10 wherein said nonwoven web is adapted to fit an automobile cabin air filtration system.
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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) | 2001-01-19 | 2001-07-21 | 2002-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-19 | 2005-07-21 | 2006-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-19 | 2009-07-21 | 2010-01-20 | $7700.00 | Window Closed / Lapsed |