GYPSUM-CONTAINING FIRE-RESISTANT STRUCTURAL FIBERBOARD

摘要

An isometric view of fire door construction (60) comprising gypsum fiberboard pa nels (62) having a density of at leat 60 lbs/ft3, a flexural strength of at least 30 lbs (1/2) inch thick material), and a screw holding capacity of at least 400 lbs. Said panel has a composition comprising 65 wt % to 90 wt % gypsum dihydrate, 7 wt % t o 30 wt % paper fiber, and a performance booster selected from inorganic fiber, clay, vermiculite, and binder polymer. Th e honeycomb structure (66) is surrounded at the door perimeter by gypsum fiberboard edge banding (65) with a preferred densi ty of 65 lbs/ft3 and a screw holding capacity of at least 600 lbs/ft3.