Fire-resistant structure containing gypsum fiberboard
AssigneeGeorgia-Pacific Corporation
InventorsTurner W. Richards, Hubert C. Francis, George F. Fowler
Life of this patent
Estimating the term…
Abstract
Fire-resistant structures are provided having at least a 20 minute ASTM E-152 fire test rating. The structures include a core having a gypsum-containing composition and a density of at least about 60 lbs/ft, a flexural strength of at least 30 lbs (1/2 inch thick material), and a screw-holding capacity of at least about 400 lbs. The gypsum-containing composition further contains a substantially uniform distribution of solids including about 65 wt. % to about 90 wt. % set gypsum dihydrate, about 7 wt. % to about 30 wt. % paper fiber, and about 1.5 wt. % to about 35 wt. % of one or more performance boosters selected from inorganic fiber, clay, vermiculate, and binder polymer.
Claims42
A fire-resistant structure, suitable for use in fire door applications, said structure having at least a 20 minute ASTM E-152 fire test rating, said structure comprising:
- a core including a gypsum-containing composition having a density of at least about 60 lbs/ft.sup.3, a flexural strength of at least about 30 lbs (1/2 inch thick material), and a screw-holding capacity of at least about 400 lbs, said having a density of at least about 60 lbs/ft.sup.3, a flexural strength of at least about 30 lbs (1/2 inch thick material), and a screw-holding capacity of at least about 400 lbs, said composition containing a substantially uniform distribution of solids including about 65 wt. % to about 90 wt. % set gypsum dihydrate, about 7 wt. % to about 30 wt. % paper fiber, and one or more performance boosters selected from inorganic fiber, clay, vermiculite, and binder polymer.
A fire door having at least a 20 minute ASTM E-152 fire test rating, said door comprising:
- a core including at least a pair of unfaced gypsum fiberboard panels containing a composition comprising about 75 wt. % to about 90 wt. % gypsum dihydrate, about 10 wt. % to about 17 wt. % paper fiber, and one or more performance boosters selected from inorganic fiber, clay, vermiculite, and binder polymer, said unfaced gypsum fiberboard panels having a flexural strength of at least about 30 lbs (1/2 inch thick material), a screw-holding capacity of at least about 400 lbs, and a wood-like veneer disposed substantially over said core.
A fire door having at least a 45 minute ASTM E-152 fire test rating, said door comprising:
- (a) a core including at least a pair of gypsum-containing fiberboard panels having a combined thickness of greater than about 3/4 inches, said fiberboard panels having a density of at least about 60 lbs/ft.sup.3 and including a composition containing about 65 wt. % to about 90 wt. % set gypsum dihydrate and about 7 wt. % to about 30 wt. % paper fiber;
- and
- (b) a paper-containing honeycomb-like structure disposed between said fiberboard panels.
A fire door having at least a 60 minute ASTM E-152 fire test rating, said door comprising:
- (a) a core including at least a pair of gypsum-containing fiberboard panels having a combined thickness of greater than about 1 inch, said fiberboard panels having a density of at least about 60 lbs/ft.sup.3 and including a composition containing about 65 wt. % to about 90 wt. % set gypsum dihydrate and about 7 wt. % to about 30 wt. % paper fiber, said panels having a screw holding capacity of at least about 400 lbs. and a flexural strength of at least about 30 lbs. (1/2 thick material);
- and
- (b) a paper-containing honeycomb-like structure disposed between said fiberboard panels.
A fire door having at least a 90 minute ASTM E-152 fire test rating, said door comprising:
- (a) a core comprising a fiberboard layer having a thickness of greater than about 1.5 inches, said fiberboard layer having a density of at least about 60 lbs/ft.sup.3 and including a composition containing about 65 wt. % to about 90 wt. % set gypsum dihydrate and about 7 wt. % to about 30 wt. % paper fiber, said layer having a screw holding capacity of at least about 400 lbs. and a flexural strength of at least about 30 lbs. (1/2 thick material).
A fire door having at least a 20 minute ASTM E-152 fire test rating, said door comprising a core including a pair of gypsum wallboards having a paper-containing honeycomb structure disposed therebetween, said core being substantially covered by a gypsum fiberboard veneer having a thickness of up to about 1/8 inches, said veneer having a composition comprising about 65 wt. % to about 90 wt. % set gypsum dihydrate, about 7 wt. % to about 30 wt. % paper fiber, and one or more performance boosters selected from inorganic fiber, clay, vermiculite, and binder polymer, said composition having a screw holding capacity of at least about 400 lbs. and a flexural strength of at least about 30 lbs. (1/2 inch thick material).
A gypsum fiberboard, suitable for firedoor applications, comprising a uniform mixture including about 65-90 wt. % set gypsum dihydrate and about 7-30 wt. % pulped paper fiber, said fiberboard having a flexural strength of at least about 30 lbs. (1/2 inch thick material) and a screw holding capacity of at least about 400 lbs. and a density within a range of about 40 lbs./ft..sup.3 to about 75 lbs./ft..sup.3.
Dependencies are inferred from the claim text.