US3827934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing high strength,high yield hardwood pulp
Assignee: Westvaco Corp
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Filing: 1971-06-28
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Granted: 1974-08-06
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Expires: 1991-06-28
Abstract
Abstract HIGH STRENGTH, HIGH YIELD HARDWOOD PULPS ARE PRODUCED BY PARTIALLY FIBERIZING HARDWOOD FIBERS DURING DIGESTION REMOVING DIGESTION CHEMICALS FROM THE FIBERD BY APPLYING SUFFICIENT AND THEREAFTER WASHING SAID FIBERS AND FURTHER REFIBERS AND THEREAFTER WASHING SAID FIBERS AND FURTHER REFINING SAID FIBERS SURFACES AT A RATE SUFFICIENT TO CAUSE FIBERIZ ATION ALONG THE FIBER SURFACES BY INTERFIBER FRICTION WITHOUT SUBSTANTIALLY FRACTURING SAID FIBERS. THE HARDWOOD PULP PRODUCED HAS A WILLIAM SLOWNESS OF LESS THAN 18 SECONDS FOR A 3-GRAM SAMPLE A 200 ML. K NUMBER OF AT LEAST 500 AND A DIRT LEVEL OF LESS THAN 4.0.
Inventors
- 👤 M Ringley
- 👤 P Wendelin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:36
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/22; D21C3/02; D21C3/022; D21C3/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |