US5009746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removing stickies from secondary fibers using supercritical CO2 solvent extraction
Assignee: Kimberly Clark Worldwide Inc
•
Filing: 1990-10-12
•
Granted: 1991-04-23
•
Expires: 2010-10-12
Abstract
Abstract A process for removing sticky contaminants ("stickies") from cellulose-containing fibers such as waste paper is provided. The process comprises contacting the fibers with supercritical or near supercritical carbon dioxide for a period of time sufficient to extract a substantial portion of the stickies without substantially damaging the fibers.
Inventors
- 👤 Shafi U. Hossain
- 👤 Carol A. Blaney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:39
CPC Classifications
B; B01; B01D; B01D11/00; B01D11/02; B01D11/0203; D; D21; D21C; D21C5/00; D21C5/02; D21C9/00; D21C9/08; D21C9/083; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/64; Y10; Y10S; Y10S162/00; Y10S162/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
58 words
A method for reducing the level of sticky contaminants in cellulose-containing secondary fibers containing sticky contaminants comprising contacting the fibers with carbon dioxide under pressure and temperature conditions such that the carbon dioxide is a supercritical or near supercritical fluid and for a period of time sufficient to reduce the level of sticky contaminants associated with the fibers.
Claim 2
Independent Claim
58 words
A method for reducing the level of sticky contaminants in cellulose-containing secondary fibers containing sticky contaminants comprising contacting the fibers with carbon dioxide under pressure and temperature conditions such that the carbon dioxide is a supercritical or near supercritical fluid and for a period of time sufficient to reduce the level of sticky contaminants associated with the fibers.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the pressure is above about 60 atmospheres and the temperature is above about 25° C.
Claim 4
Dependent Claim
21 words
The method of claim 2 wherein the pressure is above about 73 atmospheres and the temperature is above about 31° C.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein the pressure is less than about 300 atmospheres and the temperature is less than about 150° C.
Claim 6
Dependent Claim
30 words
The method of claim 4 wherein the pressure is between about 80 atmospheres and about 200 atmospheres and wherein the temperature is between about 31° C. and about 90° C.
Claim 7
Dependent Claim
52 words
The method of claim 1 wherein the supercritical or near supercritical carbon dioxide is flowed through the secondary fibers and wherein the rate of flow is between about 0.01 standard liters per minute per gram of dry secondary fiber and about 10.0 standard liters per minute per gram of dry secondary fiber.
Claim 8
Dependent Claim
37 words
The method of claim 6 wherein the rate of flow is between about 0.1 standard liters per minute per gram of dry secondary fiber and about 1.0 standard liters per minute per gram of dry secondary fiber.
Claim 9
Dependent Claim
28 words
The method of claim 6 wherein the supercritical or near supercritical carbon dioxide is flowed through the secondary fibers for between about one minute and about three hours.
Claim 10
Dependent Claim
28 words
The method of claim 8 wherein the supercritical or near supercritical carbon dioxide is flowed through the secondary fibers for between about 3 minutes and about one hour.
Claim 11
Dependent Claim
31 words
The method of claim 1 wherein the ratio of grams of supercritical or near supercritical carbon dioxide to the grams of dry secondary fiber is between about 10 and about 200.
Claim 12
Dependent Claim
12 words
The method of claim 1 wherein the sticky contaminants comprise an adhesive,
Claim 13
Dependent Claim
12 words
The method of claim 1 wherein the sticky contaminants comprise a tackifier.
Claim 14
Dependent Claim
42 words
The method of claim 1 wherein the sticky contaminants are selected from the group consisting of polyvinyl acetate polymers, polyvinyl acetate copolymers, ethylene vinyl acetate polymers, ethylene vinyl acetate copolymers, polystyrene, styrenebutadiene polymers, polypropylene, polyethylene, polyamide, rubber compounds, wax, and mixtures thereof.
Claim 15
Dependent Claim
24 words
The method of claim 1 wherein the level of sticky contaminants in the cellulose-containing secondary fibers is reduced prior to de-inking of the fibers.
Claim 16
Dependent Claim
24 words
The method of claim 1 wherein the level of sticky contaminants in the cellulose-containing secondary fibers is reduced prior to bleaching of the fibers.
References Cited (Backward Citations)
US3058871A
Cited
US4061566A
Cited
US4193838A
Cited
US4113446A
Cited
US4147624A
Cited
US4263253A
Cited
WO1981000855A1
Cited
WO1981000854A1
Cited
US4543190A
Cited
US4338199A
Cited
US4338199B1
Cited
US4308200A
Cited
US4472442A
Cited
US4466923A
Cited
US4703060A
Cited
US4554170A
Cited
US4550198A
Cited
US4495095A
Cited
US4564458A
Cited
US4728525A
Cited
US4493797A
Cited
US4675198A
Cited
US4594164A
Cited
US4647466A
Cited
US4767634A
Cited
EP0314223A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-04-22 | 1994-10-22 | 1995-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-22 | 1998-10-22 | 1999-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-22 | 2002-10-22 | 2003-04-23 | $7700.00 | Window Closed / Lapsed |