US2854334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapid kraft pulping process for bagasse and other fibrous, non-woody lignocellulosic plant materials
Assignee: HAWAIIAN DEV CO Ltd
•
Filing: 1954-11-08
•
Granted: 1958-09-30
•
Expires: 1974-11-08
Abstract
No abstract record available.
Inventors
- 👤 Samuel B Knapp
- 👤 James D Wethern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:50
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/02; D21C3/022
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
THE PROCESS OF PULPING FIBROUS, NON-WOODY, LIGNOCELLULOSIC PLANT MATERIALS WHICH COMPRISES FORMING A MIXTURE COMPRISING THE PLANT MATERIAL AND AN AQUEOUS DIGESTING LIQUOR CONTAINING AS ACTIVE PULPING AGENTS NAOH AND NA2S, THE MIXTURE BEING CHARACTERIZED BY A RATIO OF THE LIQUOR TO OVEN DRY PLANT MATERIAL OF FROM 2:1 TO 15:1 AND A SULFIDITY OF 15-35%, THE COMBINED AMOUNT OF NAOH AND NA2S BEING FROM 6 TO 20% BASED ON THE WEIGHT OF OVEN DRY PLANT MATERIAL, HEATING THE MIXTURE UNDER PRESSURE TO A TEMPERATURE OF FROM 140 210*C. OVER A TIME PERIOD OF UP TO 15 MINUTES, AND MAINTAINING THE MIXTURE UNDER PRESSURE AT 140-210*C. FOR A TIME PERIOD OF FROM 30 SECONDS TO 5 MINUTES.
Claim 2
Dependent Claim
117 words
THE PROCESS OF PULPING FIBROUS, NON-WOODY, LIGNOCELLULOSIC PLANT MATERIALS WHICH COMPRISES FORMING A MIXTURE COMPRISING THE PLANT MATERIAL AND AN AQUEOUS DIGESTING LIQUOR CONTAINING AS ACTIVE PULPING AGENTS NAOH AND NA2S, THE MIXTURE BEING CHARACTERIZED BY A RATIO OF THE LIQUOR TO OVEN DRY PLANT MATERIAL OF FROM 2:1 TO 15:1 AND A SULFIDITY OF 15-35%, THE COMBINED AMOUNT OF NAOH AND NA2S BEING FROM 6 TO 20% BASED ON THE WEIGHT OF OVEN DRY PLANT MATERIAL, HEATING THE MIXTURE UNDER PRESSURE TO A TEMPERATURE OF FROM 140 210*C. OVER A TIME PERIOD OF UP TO 15 MINUTES, AND MAINTAINING THE MIXTURE UNDER PRESSURE AT 140-210*C. FOR A TIME PERIOD OF FROM 30 SECONDS TO 5 MINUTES.
References Cited (Backward Citations)
US296935A
Cited
US629077A
Cited
US789418A
Cited
US1387441A
Cited
US1679441A
Cited
US1782755A
Cited
US1868755A
Cited
US1991499A
Cited
US2582054A
Cited
US2662012A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-29 | 1962-03-31 | 1962-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-29 | 1966-03-31 | 1966-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-29 | 1970-03-31 | 1970-09-30 | $7700.00 | Window Closed / Lapsed |