Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: The invention provides a board forming system comprising a forming table comprising a belt with a surface for conveying a backing layer; a mixer fitted with a mechanism capable of depositing cementitious slurry material over a top surface of the backing layer; and a slurry spreader positioned downstream of the mixer, wherein a portion of the slurry spreader comprises a plurality of apertures which are connected to a source of pressurized fluid. The slurry spreader is configured such that the pressurized fluid flows out of the slurry spreader through the apertures so as to provide a continuous film of fluid across an outer surface of the slurry spreader. The slurry spreader is positioned such that it can contact at least a portion of the cementitious slurry after the slurry exits the discharge and before the slurry is spread across the width of the backing layer such that the thickness of the slurry is approximately equal to the desired slurry thickness for board formation.

Abstract: A method for producing a set gypsum-containing product comprising an interlocking matrix of set gypsum wherein said method comprises applying to said set gypsum one or more enhancing materials selected from the group consisting of phosphoric acid; condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units, and monobasic salts or monovalent ions of orthophosphates.