Patent ID: 11884040
Assignee: UNITED STATES GYPSUM COMPANY
Field: Surface technology, coating (Chemistry)
Classification: CPC B  C  Y | IPC B  C

Claim 7:
8. 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 board exhibits a nail pull resistance to core hardness ratio of from about 4 to about 8, each as determined in accordance with ASTM C-473, when the board is about ½ inch thick; and the board having a density of about 35 pcf or less.