US2904460A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous pulping process
Assignee: University of Florida
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Filing: 1953-07-22
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Granted: 1959-09-15
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Expires: 1973-07-22
Abstract
No abstract record available.
Inventors
- 👤 William J Nolan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:21
CPC Classifications
D; D21; D21C; D21C1/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
128 words
A PROCESS FOR PULPING WOOD CHIPS COMPRISING SUBJECTING THE WOOD CHIPS TO THE PULPED TO AN ALKALINE SOLUTION HAVING A PH OF ABOUT 8 AT AN ELEVATED TERMPERATURE AND PRESSURE FOR RELATIVELY SHORT PERIODS OF TIME TO SOFTEN THE LIGNIN OF THE WOOD TO PERMIT SUBDIVISION THEREOF IN THE FIBER DIRECTION, SUBJECTING THE SOFTENED WOOD TO A MECHANICAL SHREDDING ACTION TO EXPAND THE SURFACE AREA OF THE WOOD NORMAL TO THE FIBER DIRECTION INTO CHIPLENGTH SPLINTERS HAVING A CROSS-SECTIONAL DIMENSION OF FROM ABOUT 2.3 TO ABOUT 4.7 MM., AND THEN SUBJECTING THE SPLINTERS TO A DELIGNIFICATION TREATMENT OF THE CELLULOSIC MATERIAL BY THE ACTION OF A SOLUTION OF SODIUM HYDROXIDE AND SODIUM SULFIDE AT SUBSTANTIALLY CONSTANT CONCENTRATION AT A TEMPERATURE OF FROM ABOUT 300* TO ABOUT 400* F.
Claim 2
Dependent Claim
128 words
A PROCESS FOR PULPING WOOD CHIPS COMPRISING SUBJECTING THE WOOD CHIPS TO THE PULPED TO AN ALKALINE SOLUTION HAVING A PH OF ABOUT 8 AT AN ELEVATED TERMPERATURE AND PRESSURE FOR RELATIVELY SHORT PERIODS OF TIME TO SOFTEN THE LIGNIN OF THE WOOD TO PERMIT SUBDIVISION THEREOF IN THE FIBER DIRECTION, SUBJECTING THE SOFTENED WOOD TO A MECHANICAL SHREDDING ACTION TO EXPAND THE SURFACE AREA OF THE WOOD NORMAL TO THE FIBER DIRECTION INTO CHIPLENGTH SPLINTERS HAVING A CROSS-SECTIONAL DIMENSION OF FROM ABOUT 2.3 TO ABOUT 4.7 MM., AND THEN SUBJECTING THE SPLINTERS TO A DELIGNIFICATION TREATMENT OF THE CELLULOSIC MATERIAL BY THE ACTION OF A SOLUTION OF SODIUM HYDROXIDE AND SODIUM SULFIDE AT SUBSTANTIALLY CONSTANT CONCENTRATION AT A TEMPERATURE OF FROM ABOUT 300* TO ABOUT 400* F.
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) | 1962-09-14 | 1963-03-16 | 1963-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-09-14 | 1967-03-16 | 1967-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-09-14 | 1971-03-16 | 1971-09-15 | $7700.00 | Window Closed / Lapsed |