US2791503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing semichemical pulp
Assignee: Champion Paper and Fibre Co
•
Filing: 1952-05-08
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Granted: 1957-05-07
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Expires: 1972-05-08
Abstract
No abstract record available.
Inventors
- 👤 Malcolm G Lyon
- 👤 Robert P Green
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:33
CPC Classifications
D; D21; D21D; D21D1/00; D21D1/20; D21D1/30; D21D1/004; D21D1/006; D21D1/008
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
METHOD OF PREPARING SUNSTANTIALLY SHIVE-FREE SEMICHEMICAL PULP WHICH COMPRISES COOKING HARDWOOD CHIPS TO AN UNBLEACHED YIELD, BASIS WOOD , OF FROM 55% TO 70% PASSING THE RESULTANT STOCK AT A CONSISTENCY OF BETWEEN 20% AND 50% UNDER PRESSURE BETWEEN OPPOSED, RELATIVELY MOVING SURFACES EXERTING A COMBING ACTION ON SAID STOCK, SAID SURFACE BEING MAINTAINED AT A MINIMUM CLEARANCE OF AT LEAST 0.060 INCH THROUGHOUT THE COMBING ACTION, AND THE COMBING ACTION CONTINUED UNTIL THE REJECTS ON A 0.012 INCH CUT SCREEM ARE BETWEEN 2% AND 6%, THE EXTEND OF COOKING OF THE CHIPS, THE CONSISTENCY OF THE STOCK
Claim 2
Dependent Claim
98 words
METHOD OF PREPARING SUNSTANTIALLY SHIVE-FREE SEMICHEMICAL PULP WHICH COMPRISES COOKING HARDWOOD CHIPS TO AN UNBLEACHED YIELD, BASIS WOOD , OF FROM 55% TO 70% PASSING THE RESULTANT STOCK AT A CONSISTENCY OF BETWEEN 20% AND 50% UNDER PRESSURE BETWEEN OPPOSED, RELATIVELY MOVING SURFACES EXERTING A COMBING ACTION ON SAID STOCK, SAID SURFACE BEING MAINTAINED AT A MINIMUM CLEARANCE OF AT LEAST 0.060 INCH THROUGHOUT THE COMBING ACTION, AND THE COMBING ACTION CONTINUED UNTIL THE REJECTS ON A 0.012 INCH CUT SCREEM ARE BETWEEN 2% AND 6%, THE EXTEND OF COOKING OF THE CHIPS, THE CONSISTENCY OF THE STOCK
References Cited (Backward Citations)
US1878228A
Cited
US2425024A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-05-06 | 1960-11-05 | 1961-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-05-06 | 1964-11-05 | 1965-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-05-06 | 1968-11-05 | 1969-05-07 | $7700.00 | Window Closed / Lapsed |