Abstract: Provided are methods and systems for introducing a wet gypsum accelerator or other high viscosity production additive to an aqueous dispersion of calcined gypsum in a discharge apparatus downstream of a stucco mixer in which the dispersion was prepared. These methods and systems are useful in the production of various gypsum products such as board including wallboard and ceiling tiles.

Abstract: A panel includes about 0.1% to about 95% by weight of a ground renewable component. In an embodiment, the panel has at least one core comprising: from about 0.1% to about 95% by weight of the ground renewable component; from about 0.1% to about 95% by weight of one or more fibers; and from about 1% to about 30% by weight of one or more binders, all based on dry panel weight. In an embodiment, the ground renewable component has a particle size distribution whereby less than 5% of the particles are retained by a mesh screen with openings of about 0.312 inches and less than 5% of the particles pass through a mesh screen with openings of about 0.059 inches. A method for manufacturing such panels is also provided.

Abstract: Provided are methods and systems for introducing a wet gypsum accelerator or other high viscosity production additive to an aqueous dispersion of calcined gypsum in a discharge apparatus downstream of a stucco mixer in which the dispersion was prepared. These methods and systems are useful in the production of various gypsum products such as board including wallboard and ceiling tiles.

Abstract: A panel includes about 0.1% to about 95% by weight of a renewable component. The panel has at least one of a CAC value of at least about 25, an NRC value of at least about 0.25 and an STC of at least about 25. A method for manufacturing such panels is also provided.

Abstract: The acoustical product of the present invention comprises an acoustical product including a matrix of calcium sulfate dihydrate crystals and expanded perlite distributed throughout the matrix. The expanded perlite has a particle size distribution with at least 10% of the perlite having a particle diameter of 700 microns or more, and the amount of expanded perlite to calcium sulfate dihydrate is about 35% to about 75% by weight, based upon the dry weight of the calcium sulfate dihydrate. A dispersing agent and glass fibers having a particle length of about ¼ inch to about 1 inch are dispersed throughout the gypsum matrix.

Abstract: Provided are methods and systems for introducing a wet gypsum accelerator or other high viscosity production additive to an aqueous dispersion of calcined gypsum in a discharge apparatus downstream of a stucco mixer in which the dispersion was prepared. These methods and systems are useful in the production of various gypsum products such as board including wallboard and ceiling tiles.

Abstract: A panel includes about 0.1% to about 95% by weight of a renewable component. The panel has at least one of a CAC value of at least about 25, an NRC value of at least about 0.25 and an STC of at least about 25. A method for manufacturing such panels is also provided.

Abstract: A panel includes about 0.1% to about 95% by weight of a renewable component. The panel has at least one of a CAC value of at least about 25, an NRC value of at least about 0.25 and an STC of at least about 25. A method for manufacturing such panels is also provided.

Abstract: A panel includes about 0.1% to about 95% by weight of a renewable component. The panel has at least one of a CAC value of at least about 25, an NRC value of at least about 0.25 and an STC of at least about 25. A method for manufacturing such panels is also provided.

Abstract: A panel includes about 0.1% to about 95% by weight of a ground renewable component. In an embodiment, the panel has at least one core comprising: from about 0.1% to about 95% by weight of the ground renewable component; from about 0.1% to about 95% by weight of one or more fibers; and from about 1% to about 30% by weight of one or more binders, all based on dry panel weight. In an embodiment, the ground renewable component has a particle size distribution whereby less than 5% of the particles are retained by a mesh screen with openings of about 0.312 inches and less than 5% of the particles pass through a mesh screen with openings of about 0.059 inches. A method for manufacturing such panels is also provided.

Abstract: A process is disclosed for making a blend of alpha- and beta-stucco including a slurry calcination step to produce alpha calcium sulfate hemihydrate followed by a fluidized bed calcination step to produce beta calcium sulfate hemihydrate. The process starts with 50-75% gypsum-containing solids slurry, and then steam calcines the slurry in a first reactor to form partially calcined gypsum slurry which contains calcium sulfate dihydrate and alpha calcium sulfate hemihydrate. The partially calcined slurry is then dewatered. Then the filter cake is fed into a kettle to complete the calcination process by converting the calcium sulfate dihydrate of the filter cake material into beta calcium sulfate hemihydrate.

Abstract: The acoustical product of the present invention comprises an acoustical product including a matrix of calcium sulfate dihydrate crystals and expanded perlite distributed throughout the matrix. The expanded perlite has a particle size distribution with at least 10% of the perlite having a particle diameter of 700 microns or more, and the amount of expanded perlite to calcium sulfate dihydrate is about 35% to about 75% by weight, based upon the dry weight of the calcium sulfate dihydrate. A dispersing agent and glass fibers having a particle length of about ¼ inch to about 1 inch are dispersed throughout the gypsum matrix.