US2639989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of cellulosic pulps
Assignee: United States Gypsum Co
•
Filing: 1946-04-25
•
Granted: 1953-05-26
•
Expires: 1966-04-25
Abstract
No abstract record available.
Inventors
- 👤 James H Conover
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:28
CPC Classifications
D; D21; D21J; D21J1/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
86 words
PROCESS OF MAKING FIBER BOARD WHICH COMPRISES SUSPENDING GROUND WOOD FIBERS IN WATER TO FORM A FIBER FURNISH, MECHANICALLY WORKING SAID FURNISH TO HYDRATE THE FIBERS THEREIN, ADDING ENOUGH LIME, WITHIN THE RANGE OF FROM ABOUT 1% TO ABOUT 24% BY WEIGHT OF THE DRY FIBERS, TO INCREASE THE FREENESS OF THE FURNISH BY FROM ABOUT 65 CC. TO ABOUT 175 CC. OVER ITS ORIGINAL FREENESS, FORMING THE RESULTING FURNISH INTO A WET MAT, COMPRESSING THE LATTER TO EXPRESS FREE WATER THEREFROM, AND DRYING THE MAT.
Claim 2
Dependent Claim
86 words
PROCESS OF MAKING FIBER BOARD WHICH COMPRISES SUSPENDING GROUND WOOD FIBERS IN WATER TO FORM A FIBER FURNISH, MECHANICALLY WORKING SAID FURNISH TO HYDRATE THE FIBERS THEREIN, ADDING ENOUGH LIME, WITHIN THE RANGE OF FROM ABOUT 1% TO ABOUT 24% BY WEIGHT OF THE DRY FIBERS, TO INCREASE THE FREENESS OF THE FURNISH BY FROM ABOUT 65 CC. TO ABOUT 175 CC. OVER ITS ORIGINAL FREENESS, FORMING THE RESULTING FURNISH INTO A WET MAT, COMPRESSING THE LATTER TO EXPRESS FREE WATER THEREFROM, AND DRYING THE MAT.
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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) | 1956-05-25 | 1956-11-24 | 1957-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-25 | 1960-11-24 | 1961-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-25 | 1964-11-24 | 1965-05-26 | $7700.00 | Window Closed / Lapsed |