US2811518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alkaline refining of wood pulp
Assignee: Rayonier Inc
•
Filing: 1955-06-07
•
Granted: 1957-10-29
•
Expires: 1975-06-07
Abstract
No abstract record available.
Inventors
- 👤 Mitchell Reid Logan
- 👤 Else S Schlosser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:17
CPC Classifications
C; C08; C08B; C08B1/00; D; D21; D21C; D21C9/00; D21C9/001
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
106 words
THE METHOD OF REFINING AND DEPOLYMERIZING WOOD PULP WHICH COMPRISES SUBJECTING A PULP WHICH HAS BEEN PREVIOUSLY SUBJECTED TO A DIGESTION TREATMENT TO AN ALKALINE REFINING OPERATION CHARACTERIZED BY THE USE OF AN ALKALINE SOLUTION EQUIVALENT TO 0.2 TO 6% OF NAOH IN SOLUTION AND A PULP CONSISTENCY OF FRON 28% TO 60% WHEREBY THE PULP IS IN A LOOSE POROUS MASS FREE OF SURFACE LIQUID FILM, CARRYING OUT THE ALKALINE REFINING AT A TEMPERATURE OF FROM 50*C., APPLYING AN EXCESS OF GASEOUS OXYGEN TO THE POROUS PULP MASS DURING THE ALKALINE REFINING, AND WASHING THE PULP, THEREBY FORMING A PULP HAVING RELATIVELY LOW AGING REQUIREMENT.
Claim 2
Independent Claim
106 words
THE METHOD OF REFINING AND DEPOLYMERIZING WOOD PULP WHICH COMPRISES SUBJECTING A PULP WHICH HAS BEEN PREVIOUSLY SUBJECTED TO A DIGESTION TREATMENT TO AN ALKALINE REFINING OPERATION CHARACTERIZED BY THE USE OF AN ALKALINE SOLUTION EQUIVALENT TO 0.2 TO 6% OF NAOH IN SOLUTION AND A PULP CONSISTENCY OF FRON 28% TO 60% WHEREBY THE PULP IS IN A LOOSE POROUS MASS FREE OF SURFACE LIQUID FILM, CARRYING OUT THE ALKALINE REFINING AT A TEMPERATURE OF FROM 50*C., APPLYING AN EXCESS OF GASEOUS OXYGEN TO THE POROUS PULP MASS DURING THE ALKALINE REFINING, AND WASHING THE PULP, THEREBY FORMING A PULP HAVING RELATIVELY LOW AGING REQUIREMENT.
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) | 1960-10-28 | 1961-04-29 | 1961-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-28 | 1965-04-29 | 1965-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-28 | 1969-04-29 | 1969-10-29 | $7700.00 | Window Closed / Lapsed |