Patent US3944698A successfully refreshed from Google Patents.
US3944698A
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Gypsum wallboard and process for making same
Assignee: United States Gypsum Co
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Filing: 1973-11-14
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Granted: 1976-03-16
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Expires: 1993-11-14
Abstract
Abstract A specially prepared fiber reinforcement and improved gypsum wallboard are disclosed. The fiber reinforcement includes a multiplicity of relatively long fibers which are disposed at the interface of the core and cover sheets of the wallboard and are adhesively bonded to the cover sheets and incorporated predominantly into the portion of the core immediately adjacent to the cover sheets.
Inventors
- 👤 Robert P. Dierks
- 👤 Robert J. Rillie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:38
CPC Classifications
B; B28; B28B; B28B1/00; B28B1/52; B28B1/522; B32; B32B; B32B13/00; B32B13/04; B32B13/08; B28B1/526; B28B19/00; B28B19/0092; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/16; B29C70/20; B29C70/202; E; E04; E04C; E04C2/00; E04C2/02; E04C2/04; E04C2/043; E04C2/06; B32B2262/00; B32B2262/10; B32B2262/101; B32B2305/00; B32B2305/08; B32B2307/00; B32B2307/50; B32B2307/546; B32B2607/00; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249924; Y10T428/249932; Y10T428/249953; Y10T428/249967; Y10T428/249968; Y10T428/31504; Y10T428/31971; Y10T428/31975; Y10T428/31978; Y10T428/31982
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
100 words
In a gypsum board having a set gypsum core securely bonded to paper cover sheets; the improvement comprising a plurality of glass reinforcing fibers in the gypsum core wherein a majority of said fibers are disposed immediately adjacent the interface of the core and at least one of the cover sheets, said fibers being of an average length sufficiently great so that they are frictionally gripped by the core with such force that said fibers will break off rather than pull out of the core when said fibers are subjected to external tension, and being bonded to the cover sheet.
Claim 2
Dependent Claim
100 words
In a gypsum board having a set gypsum core securely bonded to paper cover sheets; the improvement comprising a plurality of glass reinforcing fibers in the gypsum core wherein a majority of said fibers are disposed immediately adjacent the interface of the core and at least one of the cover sheets, said fibers being of an average length sufficiently great so that they are frictionally gripped by the core with such force that said fibers will break off rather than pull out of the core when said fibers are subjected to external tension, and being bonded to the cover sheet.
Claim 3
Dependent Claim
26 words
The improved gypsum board as defined in claim 1 wherein the average length of said fibers is greater than twice the length defined in claim 1.
Claim 4
Dependent Claim
31 words
The improved gypsum board as defined in claim 1 wherein said fibers are on the average greater than 10 inches in length for a core density of about 40 lbs./cu. ft.
Claim 5
Dependent Claim
32 words
The improved gypsum board as defined in claim 1 wherein said fibers are oriented at least partially in a direction transverse to the orientation of the fibers in the paper cover sheet.
Claim 6
Dependent Claim
27 words
The improved gypsum board as defined in claim 1 wherein said fibers are disposed at the interfaces of each of the two cover sheets and the core.
Claim 7
Dependent Claim
44 words
The improved gypsum board as defined in claim 5 wherein said fibers are disposed at the interface in an amount of at least 3 pounds per 1000 square feet of interface yet insufficient to adversely affect the bond between the core and cover sheet.
Claim 8
Dependent Claim
20 words
The improved gypsum board as defined in claim 1 wherein said fibers are in the form of substantially continuous strands.
Claim 9
Dependent Claim
14 words
The improved gypsum board as defined in claim 7 wherein said strands are undulated.
Claim 10
Dependent Claim
24 words
The improved gypsum board as defined in claim 1 wherein said fibers are glass and are in the form of an open fiber mat.
Claim 11
Dependent Claim
19 words
The improved gypsum board as defined in claim 9 wherein said fibers are in the form of a scrim.
Claim 12
Dependent Claim
25 words
The improved gypsum board as defined in claim 9 wherein said fibers are in the form of a chopped strand mat with random fiber orientation.
Claim 13
Dependent Claim
20 words
The improved gypsum board as defined in claim 1 wherein said fibers are bonded to the cover sheet by starch.
Claim 14
Dependent Claim
21 words
The improved gypsum board as defined in claim 1 wherein said fibers are bonded to the cover sheet by polyvinyl alcohol.
Claim 15
Dependent Claim
25 words
The improved gypsum board as defined in claim 1 wherein said fibers are incorporated into the portion of the core only adjacent the cover sheet.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |