CPC B32B 13/08 (2013.01) [B32B 3/26 (2013.01); B32B 5/02 (2013.01); B32B 13/14 (2013.01); B32B 17/02 (2013.01); B32B 29/00 (2013.01); C04B 28/14 (2013.01); C04B 2111/0062 (2013.01); C04B 2111/40 (2013.01); Y10T 428/249968 (2015.04)] | 20 Claims |
1. A method of making a light weight gypsum board, the method comprising:
(A) preparing a gypsum slurry having foam dispersed therein;
(B) disposing the gypsum slurry between a first cover sheet and a second cover sheet to form a panel;
(C) cutting the panel into a board of predetermined dimensions; and
(D) drying the board;
such that a set gypsum core comprising a gypsum crystal matrix is formed between the cover sheets, the gypsum crystal matrix defining walls surrounding and between air voids within the gypsum crystal matrix, the average thickness of the walls between the air voids being about 30 microns to about 200 microns, the average air void size being less than about 100 microns in diameter, the average wall thickness and air void size measured using three-dimensional imaging acquired by X-ray CT-scanning analysis (XMT), and the gypsum crystal matrix formed such that the set gypsum core has an average core hardness of at least about 11 pounds as determined in accordance with ASTM C-473; and the board having a density of about 35 pcf or less.
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