US2701763A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of manufacturing pulp from cellulosic fibrous materials
Assignee: Individual
•
Filing: 1947-11-06
•
Granted: 1955-02-08
•
Expires: 1967-11-06
Abstract
No abstract record available.
Inventors
- 👤 Sivola George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:33
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/22; D21C3/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
157 words
AN IMPROVED THREE-PHASE MANUFACTURING PROCESS FOR THE PRODUCTION OF PULP FROM CELLULOSIC FIBROUS MATERIAL WHICH COMPRISES MAKING CHIPS OF CELLULOSIC FIBROUS MATERIAL, DIGESTING AS A FIRST PHASE SAID CHIPS IN A DIGESTER IN A WEAK ACID COOKING LIQUOR CONSISTING ESSENTIALLY OF A BISULFITE OF THE GROUP CONSISTING OF SODIUM, POTASSIUM AND AMMONIUM AND CONTAINING AN EXCESS OF SULFUR DIOXIDE, THE SAID WEAK ACID LIQUOR HAVING A TOTAL SULFUR DIOXIDE CONTENT OF ABOUT 5% TO ABOUT 10%, A COMBINED SO2 CONTENT OF ABOUT 0.05% TO ABOUT 1.5%, AND A FREE SO2 CONTENT OF ABOUT 4.25% TO ABOUT 8.5%, MAINTAINING A DIGESTING PRESSURE WITHIN SAID DIGESTER OR ABOUT 75 TO ABOUT 150 POUNDS PER SQUARE INCH, CONTINUING THE WEAK ACID DIGESTING FOR ABOUT 3 HOURS WHILE RAISING THE TEMPERATURE TO ABOUT 100* C. TO PRODUCE PARTLY DIGESTED PULP AND TO REDUCE THE SULFUR DIOXIDE CONTENT TO LESS THAN ABOUT 1%, INCREASING THE TEMPERATURE TO WITHIN A RANGE OF ABOUT
Claim 2
Dependent Claim
157 words
AN IMPROVED THREE-PHASE MANUFACTURING PROCESS FOR THE PRODUCTION OF PULP FROM CELLULOSIC FIBROUS MATERIAL WHICH COMPRISES MAKING CHIPS OF CELLULOSIC FIBROUS MATERIAL, DIGESTING AS A FIRST PHASE SAID CHIPS IN A DIGESTER IN A WEAK ACID COOKING LIQUOR CONSISTING ESSENTIALLY OF A BISULFITE OF THE GROUP CONSISTING OF SODIUM, POTASSIUM AND AMMONIUM AND CONTAINING AN EXCESS OF SULFUR DIOXIDE, THE SAID WEAK ACID LIQUOR HAVING A TOTAL SULFUR DIOXIDE CONTENT OF ABOUT 5% TO ABOUT 10%, A COMBINED SO2 CONTENT OF ABOUT 0.05% TO ABOUT 1.5%, AND A FREE SO2 CONTENT OF ABOUT 4.25% TO ABOUT 8.5%, MAINTAINING A DIGESTING PRESSURE WITHIN SAID DIGESTER OR ABOUT 75 TO ABOUT 150 POUNDS PER SQUARE INCH, CONTINUING THE WEAK ACID DIGESTING FOR ABOUT 3 HOURS WHILE RAISING THE TEMPERATURE TO ABOUT 100* C. TO PRODUCE PARTLY DIGESTED PULP AND TO REDUCE THE SULFUR DIOXIDE CONTENT TO LESS THAN ABOUT 1%, INCREASING THE TEMPERATURE TO WITHIN A RANGE OF ABOUT
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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) | 1958-02-07 | 1958-08-09 | 1959-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-02-07 | 1962-08-09 | 1963-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-02-07 | 1966-08-09 | 1967-02-08 | $7700.00 | Window Closed / Lapsed |