US3674434A
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US
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Method and apparatus for determining lignin content
Assignee: Potlatch Forests Inc
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Filing: 1970-07-28
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Granted: 1972-07-04
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Expires: 1990-07-28
Abstract
Abstract A METHOD AND APPARATUS FOR DETERMINING LIGNIN CONTENT OF WOOD OR WOOD PULP BY DIRECT MEASUREMENT. THE PROCESS IS BASED UPON A THEORETICAL RELATIONSHIP BETWEEN LIGNIN CONTENT AND THE RATIO OF ELEMENTAL CARBON TO ELEMENTAL HYDROGEN IN A SAMPLE OF WOOD MATERIAL. IT INVOLVES REDUCTION OF PARTICLE SIZE AS NECESSARY FOR ELEMENTAL ANALYSIS, WASHING OF A SAMPLE, DRYING THE SAMPLE TO A PREDETERMINED MOISTURE CONTENT AND ANALYSIS OF THE SAMPLE TO DETERMINE THE ELEMENTAL RATIO OF CARBON TO HYDROGE. THE LIGNIN CONTENT OF THE SAMPLE IS THEN DETERMINED ACCORDING TO A LINEAR RELATIONSHIP. THE APPARATUS COMPRISES COMPONENTS CHOSEN TO CARRY OUT THE METHOD STEPS.
Inventors
- 👤 Charles R Pottenger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:00
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/46; Y; Y10; Y10S; Y10S162/00; Y10S162/09; Y10S162/10; Y10S162/11; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222; Y10T436/143333
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References Cited (Backward Citations)
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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) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |