Patent US2209608A successfully refreshed from Google Patents.
Patent US2962412A successfully refreshed from Google Patents.
US2962412A
Expired / Lapsed
US
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Process of manufacturing wood pulp
Assignee: Mead Corp
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Filing: 1957-10-22
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Granted: 1960-11-29
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Expires: 1977-10-22
Abstract
No abstract record available.
Inventors
- 👤 Cloyd B Richardson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:18
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/04; D21C3/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
A PROCESS FOR THE PRODUCTION OF WOOD PULP WHICH COMPRISES TREATING WOOD CHIPS IN A DIGESTER WITH A NEUTRAL LIQUOR CONTAINING ESSENTIALLY SODIUM SULFITE IN AN AMOUNT TO PROVIDE A CHEMICAL RATIO OF THE ORDER OF 42.5 PERCENT SODIUM SULFITE AND A LIQUOR TO WOOD RATIO OF THE ORDER OF 3.8 PARTS LIQUOR TO 1 PART OF WOOD, COOKING SAID WOOD CHIPS WITH SAID LIQUOR UNDER TEMPERATURE CONDITIONS OF THE ORDER OF 160*C. FOR AT LEAST 0.5 HOUR AND NOT MORE THAN 4.5 HOURS, REMOVING THE LIQUOR AND THEREAFTER CONTINUING THE COOKING OF THE WOOD CHIPS IN THE VAPOR PHASE FOR ABOUT 0.5 HOUR WHEREBY A HIGH YIELD OF RELATIVELY HIGH STRENGTH PULP IS PRODUCED WITH A MINIMUM CONSUMPTION OF SAID SODIUM SULFITE.
Claim 2
Dependent Claim
123 words
A PROCESS FOR THE PRODUCTION OF WOOD PULP WHICH COMPRISES TREATING WOOD CHIPS IN A DIGESTER WITH A NEUTRAL LIQUOR CONTAINING ESSENTIALLY SODIUM SULFITE IN AN AMOUNT TO PROVIDE A CHEMICAL RATIO OF THE ORDER OF 42.5 PERCENT SODIUM SULFITE AND A LIQUOR TO WOOD RATIO OF THE ORDER OF 3.8 PARTS LIQUOR TO 1 PART OF WOOD, COOKING SAID WOOD CHIPS WITH SAID LIQUOR UNDER TEMPERATURE CONDITIONS OF THE ORDER OF 160*C. FOR AT LEAST 0.5 HOUR AND NOT MORE THAN 4.5 HOURS, REMOVING THE LIQUOR AND THEREAFTER CONTINUING THE COOKING OF THE WOOD CHIPS IN THE VAPOR PHASE FOR ABOUT 0.5 HOUR WHEREBY A HIGH YIELD OF RELATIVELY HIGH STRENGTH PULP IS PRODUCED WITH A MINIMUM CONSUMPTION OF SAID SODIUM SULFITE.
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) | 1963-11-29 | 1964-05-30 | 1964-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-11-29 | 1968-05-30 | 1968-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-11-29 | 1972-05-30 | 1972-11-29 | $7700.00 | Window Closed / Lapsed |