Patent US4283186A successfully refreshed from Google Patents.
US4283186A
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Method of forming cigarette filter material
Assignee: Celanese Corp
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Filing: 1978-08-28
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Granted: 1981-08-11
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Expires: 1998-08-28
Abstract
Abstract A non-woven cellulose ester fibrous filter sheet material comprising cellulose ester staple fibers and cellulose ester fibrets which exhibits improved filtration properties and the method of its preparation.
Inventors
- 👤 Charles H. Keith
- 👤 Richard O. Tucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:45
CPC Classifications
D; D21; D21H; D21H13/00; D21H13/02; D21H13/06; A; A24; A24D; A24D3/00; A24D3/06; A24D3/08; A24D3/10; B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/18; D01; D01D; D01D5/00; D01D5/06; D01F; D01F2/00; D01F2/24; D01F2/28; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1007; Y10T156/1008; Y10T156/101
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
74 words
A method of producing a cigarette filter rod comprising preparing a coherent self-supporting filter sheet material of cellulose ester staple fibers having from about 5% to about 35% of cellulose ester fibrets incorporated therein, said filter sheet material having a surface area in excess of 1 square meter per gram, folding said filter sheet material into a rod-like form and then securing the folded sheet in rod-like form by means of a wrapping strip.
Claim 2
Independent Claim
74 words
A method of producing a cigarette filter rod comprising preparing a coherent self-supporting filter sheet material of cellulose ester staple fibers having from about 5% to about 35% of cellulose ester fibrets incorporated therein, said filter sheet material having a surface area in excess of 1 square meter per gram, folding said filter sheet material into a rod-like form and then securing the folded sheet in rod-like form by means of a wrapping strip.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein said filter sheet material is corrugated prior to being folded into rod-like form.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein said filter sheet material is layered with a web of cellulose acetate cigarette tow prior to folding into rod-like form.
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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) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |