Fire resistant gypsum board containing mineral wool fibers and method
AssigneeUnited States Gypsum Company
InventorMohammad H. Ali
Life of this patent
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Abstract
Blown mineral wool fibers are introduced into slurries (such as gypsum board core formulations and steel column fireproofing plaster formulations) by first blending and coating the blown mineral wool with a powdered calcium sulfate to produce a light, open nodulated effect. When mixed into aqueous calcined gypsum slurries, the nodules open up, thoroughly dispersing the mineral wool--calcium sulfate blend in the aqueous slurry and contributing fire resistant properties to the set gypsum product.
Claims27
A gypsum composition suitable for forming the core of a gypsum board which will provide at least a one hour fire resistance rating by laboratory fire test, which comprises:
- the set solids from a calcined gypsum slurry having distributed therethrough about 1-5% by weight of mineral wool fibers.
A plaster blend composition suitable for forming fire resistant gypsum compositions, which comprises calcined gypsum plaster and about 1-10% mineral wool fibers distributed therethrough resultant from blending about 1-10 parts by weight of calcium sulfate per each part by weight of wool fibers.
A method of forming a fiber reinforced and fire resistant gypsum board wherein a quantity of a mineral fiber is added to a calcined gypsum slurry, the improvement comprising:
- tumbling together wool fiber and about 1-10 parts by weight of calcium sulfate per each part by weight of wool to form a blend of wool and calcium sulfate
- feeding the blend to a gypsum board slurry mixer and mixing about 1-5% by weight of wool with water and calcined gypsum to form a slurry;
- and
- feeding the slurry to a gypsum board forming line and forming a gypsum board having a core of casty gypsum containing about 1-5% by weight of wool fiber dispersed throughout the core.
An article for use in manufacture consisting essentially of an intimate, intersticial mixture of nodules of blown mineral wool fibers coated with powdered calcium sulfate solids.
A process of manufacturing an intimate, intersticial mixture of nodules of blown mineral wool fibers and calcium sulfate comprising a tumbling blending of blown mineral wool with calcium sulfate sufficient to coat the wool fibers with powdered calcium sulfate.
Dependencies are inferred from the claim text.