US5022964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nonwoven fibrous web for tobacco filter
Assignee: AHLSTROM DEXTER LLC
•
Filing: 1989-06-06
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Granted: 1991-06-11
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Expires: 2009-06-06
Abstract
Abstract A nonwoven fibrous web material that contains cellulose ester fibers, cellulose ester fibrets and a minor amount of activated fusible fibers uniformly dispersed throughout is particularly well suited as a filter media. The activated fusible fibers are effective for retaining within the filter web any particulate material resulting from corrugation without adversely affecting the filtration efficiency of the cellulose ester fibers and fibrets. Alternatively, the fibrous web material may include an effective amount of natural cellulosic fibers.
Inventors
- 👤 L. Paul Crane
- 👤 H. Clark Lind
- 👤 Martine E. Frederix
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:15
CPC Classifications
A; A24; A24D; A24D3/00; A24D3/06; A24D3/14; A24D3/08; A24D3/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
67 words
A nonwoven fibrous web material for use as a filter media comprising cellulose ester fibers, cellulose ester fibrets and a minor amount of activated fusible fibers uniformly dispersed throughout the cellulose ester fibers and fibrets, said activated fusible fibers being present in an amount effective for retaining particulate material within the web material without substantially adversely affecting the filtration efficiency of the cellulose ester fibers and fibrets.
Claim 2
Dependent Claim
67 words
A nonwoven fibrous web material for use as a filter media comprising cellulose ester fibers, cellulose ester fibrets and a minor amount of activated fusible fibers uniformly dispersed throughout the cellulose ester fibers and fibrets, said activated fusible fibers being present in an amount effective for retaining particulate material within the web material without substantially adversely affecting the filtration efficiency of the cellulose ester fibers and fibrets.
Claim 3
Dependent Claim
27 words
The fibrous web material of claim 1 wherein the fusible fibers are heat activated to effectively bond adjacent ester fibers and fibrets during drying of the web.
Claim 4
Dependent Claim
29 words
The fibrous web material of claim 1 wherein the fusible fibers are selected from the group consisting of polyvinyl alcohol, vinyl copolymers, polyethylene, polypropylene, bicomponent fibers and mixtures thereof.
Claim 5
Dependent Claim
24 words
The fibrous web material of claim 1 wherein the fusible fibers are softened and swellable upon activation to adhere to adjacent fibers and fibrets.
Claim 6
Dependent Claim
15 words
The fibrous web material of claim 1 wherein the fusible fibers are polyvinyl alcohol fibers.
Claim 7
Dependent Claim
22 words
The fibrous web material of claim 1 wherein the fusible fibers constitute less than about 15% by weight of the fibrous web.
Claim 8
Dependent Claim
23 words
The fibrous web material of claim 1 wherein the fusible fibers constitute at least about 2 percent by weight of the web material.
Claim 9
Dependent Claim
43 words
The fibrous web material of claim 1 wherein the cellulose ester fibers and fibrets are selected from the group consisting of cellulose acetate, cellulose propionate, cellulose triacetate, cellulose benzoate, cellulose acetate butyrate, cellulose acetate formate, cellulose acetate propionate, benzyl cellulose and mixtures thereof.
Claim 10
Dependent Claim
36 words
The fibrous web material of claim 1 wherein the cellulose ester fibers are cellulose acetate fibers, the fibrets constitute 5-35 percent by weight of web material and the fusible fibers constitute about 4-10 percent by weight.
Claim 11
Dependent Claim
20 words
The fibrous web material of claim 1 including an effective amount up to 20% by weight of natural cellulosic fibers.
Claim 12
Dependent Claim
12 words
A tobacco filter made from the fibrous web material of claim 1.
Claim 13
Dependent Claim
12 words
A tobacco filter made from the fibrous web material of claim 9.
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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) | 1994-06-10 | 1994-12-10 | 1995-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-10 | 1998-12-10 | 1999-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-10 | 2002-12-10 | 2003-06-11 | $7700.00 | Window Closed / Lapsed |