Light weight gypsum board
AssigneeUnited States Gypsum Company
InventorsQiang Yu, Weixin David Song
Life of this patent
Estimating the term…
Abstract
This invention provides low density gypsum products. This invention also provides a method of making the low density gypsum products.
Claims38
A light weight gypsum board comprising:
- a set gypsum core disposed between two cover sheets;
- the set gypsum core comprising a gypsum crystal matrix having a pore size distribution comprising (i) water voids having a pore size less than about 5 microns in diameter, (ii) air voids having a pore size of at least about 5 microns and less than about 50 microns in diameter, (iii) air voids having a pore size from about 50 microns to about 100 microns in diameter, and (iv) air voids having a pore size greater than about 100 microns in diameter, the air voids having a pore size greater than about 100 microns in diameter comprising at least about 20% of the total void volume of the set gypsum core, the voids measured using scanning electron photomicrograph imaging;
- the air void pore size having greatest frequency is a diameter of about 100 microns or less;
- the gypsum crystal matrix disposed 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 33 pcf or less.
A light weight gypsum board comprising a set gypsum core disposed between two cover sheets, wherein the set gypsum core comprises (a) a gypsum crystal matrix with a distribution of air voids and water voids disposed therein, the air voids with a pore size of about 5 microns or greater and water voids with a pore size less than about 5 microns, in a volume ratio of air voids to water voids from about 1.8 to 1 to about 9 to 1, (b) a distribution of air voids having pore sizes of at least about 5 microns to less than about 100 microns, (c) a distribution of air voids further having pore sizes greater than about 100 microns in diameter such that the air voids having a pore size greater than about 100 microns in diameter comprise at least about 20% of the total void volume of the set gypsum core, the voids measured using scanning electron photomicrograph imaging, the air void pore size having greatest frequency is a diameter of about 100 microns or less, and (d) the board has a density from about 24 pcf to 33 pcf, and a ratio of density (pcf) to average core hardness (lb) of less than about 3.2, wherein the core hardness is determined in accordance with ASTM C473.
A light weight gypsum board comprising:
- a set gypsum core disposed between two cover sheets;
- the set gypsum core comprising a gypsum crystal matrix having a pore size distribution comprising (i) water voids having a pore size less than about 5 microns in diameter, (ii) air voids having a pore size of at least about 5 microns and less than about 50 microns in diameter, (iii) air voids having a pore size from about 50 microns to about 100 microns in diameter, and (iv) air voids having a pore size greater than about 100 microns in diameter, the air voids having a pore size greater than about 100 microns in diameter comprising at least about 20% of the total void volume of the set gypsum core, the voids measured using three-dimensional imaging acquired by X-ray CT-scanning analysis (XMT);
- the air void pore size having greatest frequency is a diameter of about 100 microns or less;
- the gypsum crystal matrix disposed 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 33 pcf or less.
A light weight gypsum board comprising a set gypsum core disposed between two cover sheets, wherein the set gypsum core comprises (a) a gypsum crystal matrix with a distribution of air voids and water voids disposed therein, the air voids with a pore size of about 5 microns or greater and water voids with a pore size less than about 5 microns, in a volume ratio of air voids to water voids from about 1.8 to 1 to about 9 to 1, (b) a distribution of air voids having pore sizes of at least about 5 microns to less than about 100 microns, (c) a distribution of air voids further having pore sizes greater than about 100 microns in diameter such that the air voids having a pore size greater than about 100 microns in diameter comprise at least about 20% of the total void volume of the set gypsum core, the voids measured using three-dimensional imaging acquired by X-ray CT-scanning analysis (XMT), the air void pore size having greatest frequency is a diameter of about 100 microns or less, and (d) the board has a density from about 24 pcf to 33 pcf, and a ratio of density (pcf) to average core hardness (lb) of less than about 3.2, wherein the core hardness is determined in accordance with ASTM C473.
Dependencies are inferred from the claim text.