| 摘要 |
<p>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.</p> |
