US4869782A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing high bulking anfractuous cellulosic fiber using anhydrous liquid ammonia
Assignee: Georgia Pacific Consumer Products LP
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Filing: 1988-02-12
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Granted: 1989-09-26
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Expires: 2008-02-12
Abstract
Abstract Anfractuous cellulose fibers exhibiting exceptional high bulking properties are produced by treatment of dry hammermilled wood cellulose fibers with anhydrous liquid ammonia at substantially atmospheric pressure. Fibrous webs of enhanced bulk are produced by preparing an aqueous furnish comprising at least ten percent by weight ammonia treated anfractuous fibers in admixture with conventional papermaking fibers.
Inventors
- 👤 John G. Nelson
- 👤 Richard E. Kajander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:22
CPC Classifications
D; D21; D21H; D21H21/00; D21H21/14; D21H21/22; D21C; D21C9/00; D21C9/001; D21C9/002; D21C9/004
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
77 words
A method for the production of high bulking anfractuous cellulosic fibers which comprises (a) dry milling hydrophilic cellulosic fibers containing no free water thereby mechanically deforming said hydrophilic fibers rendering them anfractuous; (b) wetting dry mechanically deformed cellulose fibers containing no free water from step (a) with substantially anhydrous liquid ammonia for a period of time in the range of from about five seconds to about thirty seconds, and (c) recovering resulting ammonia-treated anfractuous fibers as product.
Claim 2
Independent Claim
77 words
A method for the production of high bulking anfractuous cellulosic fibers which comprises (a) dry milling hydrophilic cellulosic fibers containing no free water thereby mechanically deforming said hydrophilic fibers rendering them anfractuous; (b) wetting dry mechanically deformed cellulose fibers containing no free water from step (a) with substantially anhydrous liquid ammonia for a period of time in the range of from about five seconds to about thirty seconds, and (c) recovering resulting ammonia-treated anfractuous fibers as product.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein ammonia fibers are removed by vaporization of ammonia therefrom.
Claim 4
Dependent Claim
37 words
A method according to claim 1 wherein the treatment with anhydrous liquid ammonia is carried out at a temperature in the range of 31 18° F. to -40° F. at the corresponding vapor pressure of said ammonia.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |