Method of manufacturing gypsum board with improved fire
The present disclosure is directed to a method of manufacturing gypsum board as well as the resulting gypsum board. The method comprises providing a gypsum slurry with a shrinkage-reducing additive comprising a metal salt of an acid, a silica, or a mixture thereof. As a result, the gypsum board includes gypsum and a shrinkage-reducing additive comprising a metal salt of an acid, a silica, or a mixture thereof. The gypsum board exhibits an area shrinkage of less than 10%.
1. A method for manufacturing a gypsum board, the method comprising:
providing a gypsum slurry including gypsum and an additive comprising a metal salt of an acid comprising barium and a sulfate, a phosphate, or a mixture thereof, wherein the additive is present in an amount of about 0.05 wt. % or more to less than 5 wt. % based on the weight of the gypsum,
wherein the gypsum board exhibits an area shrinkage of less than 20%.
2. The method according to claim 1 , wherein the metal salt of an acid includes a sulfate.
3. The method according to claim 1 , wherein the method further comprises:
providing a precursor additive to the gypsum slurry, wherein the precursor additive reacts in the slurry to form the additive.
4. The method according to claim 3 , wherein the precursor additive comprises a metal halide.
5. The method according to claim 4 , wherein the metal halide includes a chloride.
6. The method according to claim 4 , wherein the precursor additive includes barium.
7. The method according to claim 1 , wherein the additive further comprises a silica and wherein the silica comprises colloidal silica, precipitated silica, or a mixture thereof.
8. The method according to claim 7 , wherein the silica comprises colloidal silica.
9. The method according to claim 1 , wherein the additive has a particle size of less than 1 micrometer.
10. The method according to claim 1 , wherein the gypsum board exhibits an area shrinkage of less than 10%.
11. A gypsum board comprising:
gypsum and an additive comprising a metal salt of an acid comprising barium and a sulfate, a phosphate, or a mixture thereof, wherein the additive is present in an amount of about 0.05 wt. % or more to less than 5 wt. % based on the weight of the gypsum,
wherein the gypsum board exhibits an area shrinkage of less than 20%.
12. The gypsum board according to claim 11 , wherein the metal salt of an acid includes a sulfate.
13. The gypsum board according to claim 11 , wherein the additive further comprises a silica and wherein the silica comprises colloidal silica, precipitated silica, or a mixture thereof.
14. The gypsum board according to claim 13 , wherein the silica comprises colloidal silica.
15. The gypsum board according to claim 11 , wherein the additive has a particle size of less than 1 micrometer.
16. The gypsum board according to claim 11 , wherein the gypsum board exhibits an area shrinkage of less than 10%.