Gypsum board
US5116671A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1991 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Jun 7, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249977
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In the improved gypsum board in accordance with this invention, the board has a gypsum core and first and second cover sheets of fibrous material on opposing faces. The core has a first stratum parallel to and adjacent the first cover sheet. This stratum does not contain any fibers of the fibrous material. This first stratum has relatively few voids and a substantially greater density than the central portion of the core of the board. The central portion of the core has a plurality of relatively large discrete voids substantially uniformly distributed throughout the central portion of the core. These voids have substantially spherical coherent walls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.