US3832250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming gypsum boards with hardening edges
Assignee: Johns Manville Corp
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Filing: 1972-07-24
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Granted: 1974-08-27
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Expires: 1992-07-24
Abstract
Abstract A process is described for the incorporation of corn syrup into the edges of gypsum boards to harden those edges. An aqueous corn syrup solution of defined concentration is injected into the edge of a stream of semifluid gypsum "mud" or paste simultaneously with vibration of the mud. The mud is thereafter molded and compresses to form a gypsum board and the impregnated portion of the mud forms the edges of the board. The board is then heated to dry the gypsum and the resulting dried board is found to have edges which are significantly harder than the edges of untreated gypsum boards.
Inventors
- 👤 H Pearson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:57
CPC Classifications
B; B28; B28B; B28B5/00; B28B5/02; B28B5/026; B28B5/027; B28B19/00; B28B19/0092
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |