Patent US4833650A successfully refreshed from Google Patents.
Patent US3367828A successfully refreshed from Google Patents.
US3367828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hot, wet pressing technique of forming fiberboard
Assignee: Johns Manville Corp
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Filing: 1964-08-26
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Granted: 1968-02-06
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Expires: 1984-08-26
Abstract
No abstract record available.
Inventors
- 👤 David C Carter
- 👤 David E Noyes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:21
CPC Classifications
D; D21; D21J; D21J1/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
131 words
A METHOD OF MANUFACTURING CELLULOSIC SEMI-HARDBOARD HAVING A DENSITY OF ABOUT 25-50 LBS. PER CU. FT., AND A THICKNESS OF ABOUT 1/4 INCH TO ABOUT 5/8 INCH, COMPRISING THE STEPS OF FORMING A WATER-LAID MAT OF CELLULOSIC FIBERS CONTAINING ADDED BINDER, COMPRESSING SAID MAT IN A PRESS AT AN INITIAL PRESSURE IN THE RANGE OF APPROXIMATELY 1501400 P.S.I. FOR A RELATIVELY SHORT PERIOD OF TIME BUT UNTIL A SUBSTANTIAL AMOUNT OF WATER HAS BEEN EXPRESSED FROM THE MAT, REDUCING THE PRESSURE TO THE APPROXIMATE RANGE OF 5-80 P.S.I. RELEASING THE PRESSURE TO THE APPROXIMATE RANGE OF 5-80 P.S.I., RELEASING THE PRESSURE ON THE COMPRESSED WET MAT WHEN THE SOLIDS CONTENT THEREOF IS APPROXIMATELY 60-80%, REMOVING THE MAT FROM THE PRESS, AND DRYING AND BAKING THE COMPRESSED MAT TO REMOVE EXCESS WATER.
Claim 2
Independent Claim
131 words
A METHOD OF MANUFACTURING CELLULOSIC SEMI-HARDBOARD HAVING A DENSITY OF ABOUT 25-50 LBS. PER CU. FT., AND A THICKNESS OF ABOUT 1/4 INCH TO ABOUT 5/8 INCH, COMPRISING THE STEPS OF FORMING A WATER-LAID MAT OF CELLULOSIC FIBERS CONTAINING ADDED BINDER, COMPRESSING SAID MAT IN A PRESS AT AN INITIAL PRESSURE IN THE RANGE OF APPROXIMATELY 1501400 P.S.I. FOR A RELATIVELY SHORT PERIOD OF TIME BUT UNTIL A SUBSTANTIAL AMOUNT OF WATER HAS BEEN EXPRESSED FROM THE MAT, REDUCING THE PRESSURE TO THE APPROXIMATE RANGE OF 5-80 P.S.I. RELEASING THE PRESSURE TO THE APPROXIMATE RANGE OF 5-80 P.S.I., RELEASING THE PRESSURE ON THE COMPRESSED WET MAT WHEN THE SOLIDS CONTENT THEREOF IS APPROXIMATELY 60-80%, REMOVING THE MAT FROM THE PRESS, AND DRYING AND BAKING THE COMPRESSED MAT TO REMOVE EXCESS WATER.
References Cited (Backward Citations)
US2046750A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-02-05 | 1971-08-07 | 1972-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-02-05 | 1975-08-07 | 1976-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-02-05 | 1979-08-07 | 1980-02-06 | $7700.00 | Window Closed / Lapsed |