Fire-resistant gypsum building materials
AssigneeG-P Gypsum Corporation
InventorsTurner W. Richards, Hubert C. Francis, George F. Fowler
Life of this patent
Estimating the term…
Abstract
Fiberboards are provided containing at least about 65 wt. % calcium sulfate dihydrate derived from hemihydrate or anhydrous gypsum, and at least about 7 wt. % pulped paper fibers. The boards are capable of being formed into structural members having superior mechanical properties and/or fire resistance, including screw-holding capacities in excess of 650 lbs.
Claims23
A fiberboard comprising from about 65 wt. % to about 90 wt. % set gypsum derived substantially from non-fibrous gypsum hemihydrate, from about 7 wt. % to about 30 wt. % homogeneously distributed pulped paper fiber, and from about 1.5 wt. % to about 7 wt. % of inorganic fiber consisting essentially of siliceous fiber, and from about 1.5% to about 7 wt % clay, said fiberboard having a density of at least about 60 lbs./cu. ft. and a screw-holding capacity of at least about 400 lbs.
A building material comprising:
- set gypsum derived substantially from non-fibrous calcium sulfate;
- from about 7 wt. % to about 30 wt. % of substantially homogeneously distributed cellulosic fiber;
- and from about 1.5 wt. % to about 35 wt. % performance booster selected from the group consisting of binder polymer, siliceous fiber, clay, vermiculite, and combinations of two or more of these, said building material having a density of at least about 60 lbs./cu ft. and a screw holding capacity of at least about 400 lbs.
A gypsum-based building material comprising set gypsum derived substantially from non-fibrous calcium sulfate, from about 7 wt. % to about 30 wt. % of homogeneously distributed paper fiber, and from about 1.5 wt. % to about 35 wt. % performance booster selected from the group consisting of binder polymer, siliceous fiber, clay, vermiculite, and combinations of two or more of these, said building material having a density of at least about 60 lbs./cu ft. and a screw holding capacity of at least about 400 lbs.
Dependencies are inferred from the claim text.