Patent US3576710A successfully refreshed from Google Patents.
US3576710A
Expired / Lapsed
US
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Brightening of white water sludge
Assignee: NewPage Wisconsin System Inc
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Filing: 1969-07-28
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Granted: 1971-04-27
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Expires: 1989-07-28
Abstract
Abstract BRIGHTENING A SAVE-ALL SLUDGE RECOVERED FROM THE WHITEWATER OF A PAPER MAKING PROCESS WHICH COMPRISES TREATING IT WITH ZINC HYDROSULFITE PRIOR TO INTRODUCING IT TO AN AQUEOUS PAPER FURNISH, AND THE PRODUCTION OF PAPER THEREFROM OF IMPROVED BRIGHTNESS AS COMPARED TO THE EMPLOYMENT OF SLUDGE WHICH HAS NOT BEEN SO PRETREATED.
Inventors
- 👤 Robert J Mader
- 👤 Douglas E Moldenhauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:29
CPC Classifications
D; D21; D21F; D21F1/00; D21F1/66; Y; Y10; Y10S; Y10S162/00; Y10S162/09
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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |