US3067086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulping process
Assignee: Columbia Cellulose Co Ltd
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Filing: 1959-09-15
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Granted: 1962-12-04
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Expires: 1979-09-15
Abstract
No abstract record available.
Inventors
- 👤 Jack W Wilson
- 👤 O'meara Desmond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:34
CPC Classifications
D; D21; D21C; D21C1/00; D21C1/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
A PROCESS FOR THE PRODUCTION OF WOOD PULP WHICH COMPRISES CONTACTING DIVIDED WOOD WITH AN AQUEOUS COOKING LIQUOR CONTAINING AN INORGANIC BISULFITE AND HAVING A COMBINED SULFUR DIOXIDE CONTENT OF AT LEAST 3.5%, A PH NO GREATER THAN 4.5, AND A RATIO OF TOTAL TO COMBINED SULFUR DIOXIDE NO GREATER THAN 2.8 TO 1, AT A TEMPERATURE AND FOR A PERIOD OF TIME SUFFICIENT TO EFFECT THE IMPREGNATION OF THE LIQUOR INTO THE INTERSTICES OF THE WOOD, SEPARATING THE FREE LIQUOR FROM THE WOOD AFTER IMPREGNATION SUCH THAT ONLY RESIDUAL LIQUOR SURROUNDS THE PIECES OF WOOD, BUT THERE IS SUBSTANTIALLY NO LIQUOR IN THE SPACES BETWEEN SAID PIECES, AND RAISING THE WOOD TO AND MAINTAINING IT AT COOKING TEMPERATURES FOR A PERIOD SUFFICIENT TO COMPLETE THE COOK.
Claim 2
Dependent Claim
127 words
A PROCESS FOR THE PRODUCTION OF WOOD PULP WHICH COMPRISES CONTACTING DIVIDED WOOD WITH AN AQUEOUS COOKING LIQUOR CONTAINING AN INORGANIC BISULFITE AND HAVING A COMBINED SULFUR DIOXIDE CONTENT OF AT LEAST 3.5%, A PH NO GREATER THAN 4.5, AND A RATIO OF TOTAL TO COMBINED SULFUR DIOXIDE NO GREATER THAN 2.8 TO 1, AT A TEMPERATURE AND FOR A PERIOD OF TIME SUFFICIENT TO EFFECT THE IMPREGNATION OF THE LIQUOR INTO THE INTERSTICES OF THE WOOD, SEPARATING THE FREE LIQUOR FROM THE WOOD AFTER IMPREGNATION SUCH THAT ONLY RESIDUAL LIQUOR SURROUNDS THE PIECES OF WOOD, BUT THERE IS SUBSTANTIALLY NO LIQUOR IN THE SPACES BETWEEN SAID PIECES, AND RAISING THE WOOD TO AND MAINTAINING IT AT COOKING TEMPERATURES FOR A PERIOD SUFFICIENT TO COMPLETE THE COOK.
References Cited (Backward Citations)
US2640774A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-12-03 | 1966-06-04 | 1966-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-12-03 | 1970-06-04 | 1970-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-12-03 | 1974-06-04 | 1974-12-04 | $7700.00 | Window Closed / Lapsed |