Method for forming a lightweight cementitious structural product and product formed thereby
AssigneeUnited States Gypsum Company
InventorMichael D. Willoughby
Life of this patent
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Abstract
A method for producing a lightweight set cementitious product, and more specifically, gypsum wallboard, having excellent strength and paper-to-core bond, which method comprises producing a foam comprising polyvinyl alcohol and water, introducing the foam thus formed into an aqueous cementitious slurry, depositing the slurry between paper cover sheets, and permitting the cementitious slurry to set. In a further embodiment an emulsion formed of asphalt and wax is added to the cementitious slurry to impart water resistance, the polyvinyl alcohol of the foaming agent cooperating with the asphalt and wax emulsion to improve the water resistant properties of the set gypsum wallboard.
Claims16
A method for the production of a lightweight structural member, which comprises preparing a settable aqueous slurry of a cementitious material, mixing an aqueous foam into said slurry, forming said slurry into the proper shape for said structural member, and setting and drying said cementitious material, said foam being prepared by passing water and a foaming agent consisting essentially of polyvinyl alcohol through a foaming apparatus.
A lightweight structural member produced by preparing a settable aqueous slurry of a cementitious material, mixing an aqueous foam into said slurry, forming said slurry into the proper shape for said structural member, and setting and drying said cementitious material, said foam being prepared from water and a foaming agent consisting essentially of polyvinyl alcohol.
Dependencies are inferred from the claim text.