Claims
- 1. An article comprising a gypsum board, wherein the gypsum board includes a gypsum composition prepared by a method comprising:preparing a mixture formed from at least calcined gypsum and water, wherein at least 30 wt. % of said calcined gypsum is non-fibrous and wherein the weight ratio of water to calcined gypsum used to form the mixture is at least about 3:1; and maintaining the mixture under conditions sufficient for the calcined gypsum to form an interlocking matrix of set gypsum.
- 2. The article of claim 1, wherein the mixture further is formed from an enhancing material selected from the group consisting of a trimetaphosphate compound, an ammonium polyphosphate having 500-3000 repeating phosphate units, a polycarboxylic compound, a surfactant, and combinations thereof.
- 3. The article of claim 2, wherein the amount of enhancing material used to form the mixture is from about 0.01% to about 5% by weight of said calcined gypsum.
- 4. The article of claim 1, wherein said composition has a Noise Reduction Coefficient of at least about 0.4, according to ASTM E 1042-92.
- 5. The article of claim 1, wherein said composition is further formed from at least one of the following: a fibrous mat, a binder, expanded perlite, a starch, a reinforcing additive, and air voids formed by an aqueous foam.
- 6. An article comprising a gypsum board, wherein the gypsum board includes a gypsum composition prepared by a method comprising:preparing a mixture formed from at least calcined gypsum, water, and an enhancing material selected from the group consisting of a trimetaphosphate compound, an ammonium polyphosphate having 500-3000 repeating phosphate units, a polycarboxylic compound, a surfactant, and combinations thereof, wherein the weight ratio of water to calcined gypsum present in the mixture is at least about 3:1; and maintaining the mixture under conditions sufficient for the calcined gypsum to form an interlocking matrix of set gypsum.
- 7. The article of claim 6, wherein said composition has a Noise Reduction Coefficient of at least about 0.4, according to ASTM E 1042-92.
- 8. The article of claim 6, further comprising a second gypsum board, and the density of said second gypsum board is greater than the density of the gypsum composition.
- 9. The article of claim 8, further comprising wallboard paper, wherein the wallboard paper is carried on the second gypsum board.
- 10. The article of claim 8, further comprising a third gypsum board, and the density of said third gypsum board is greater than the density of the gypsum composition.
- 11. The article of claim 10, further comprising a second gypsum composition, and the density of said second gypsum composition is less than the density of the second gypsum board and the third gypsum board.
- 12. The article of claim 6, wherein the amount of enhancing material used to form the mixture is from about 0.01% to about 5% by weight of said calcined gypsum.
- 13. The article of claim 6, wherein said composition is further formed from at least one of the following a fibrous mat, a binder, expanded perlite, a starch, a reinforcing additive, and air voids formed by an aqueous foam.
RELATED APPLICATION
This is a divisional of and allowed U.S. patent application No. 09/557,636, filed Apr. 25, 2000 now U.S. Pat. No. 6,387,172.
US Referenced Citations (158)
Foreign Referenced Citations (2)
Number |
Date |
Country |
2 316 693 |
Mar 1998 |
GB |
WO 9908978 |
Feb 1999 |
WO |
Non-Patent Literature Citations (4)
Entry |
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Rong et al. “Study on the Production Process and Properties of Aeration Gypsum Insulation Panel”, pp. 1003-1008. |
“Standard Classification for Acoustically Absorptive Materials Applied by Towel or Spray” The American Society for Testing Materials (Designation: E 1042-92) pp. 814-823. |