Georgia-pacific Gypsum, Inc.

Georgia-pacific Corporation

G-p Gypsum Corporation

Hubert C Francis

George F Fowler

Turner W Richards

Anne H Ksionzyk

Susnata Samanta

Dale R Greve

George W Green

Fabio E Esguerra

Edward M Rigby

A lightweight gypsum wallboard having a foamed gypsum core reinforced with pre-gelatinized, e.g., pre-gelled, starch and prepared by mixing an aqueous foam into a gypsum slurry comprising a source of calcined gypsum (commonly known as plaster of Paris), pre-gelled starch and a lignosulfonate dispersant; allowing the so-formed gypsum slurry to set, and then drying the set gypsum core.

Lightweight gypsum wallboard

A wallboard, a method of preparing a wallboard, and a method of making a gypsum slurry to prepare a wallboard are provided. The wallboard includes a set gypsum dihydrate derived substantially from a non-fibrous form of calcium sulfate and selected from the group consisting of anhydrous gypsum and gypsum hemihydrate. The wallboard also includes an aerogel dispersed in the gypsum dihydrate.

Low thermal transmission building material

The present invention describes a fire resistant building material composition, useful for example as a fire door core and to a method of making this composition. The building material of the present invention is prepared from an aqueous mixture of predominately expanded perlite, a small amount of a binder component consisting essentially of calcined gypsum and an organic binder, and optionally a fibrous reinforcement.

Non-cement fire door core

The present invention describes an improved building material composition, useful for example as a fire door core. The building material of the present invention is prepared by compressing an aqueous mixture of expanded perlite and a fast setting, cementitious composition consisting essentially of a hydraulic cement, preferably Portland cement, and a pozzolan additive selected from the group consisting of metakaolin, VCAS and mixtures thereof, and preferably also includes an organic binder and a fibrous reinforcement.

Cement-based fire door core

The present invention describes a fire resistant building material composition, useful for example as a fire door core and to a method of making this composition where the building material of the present invention is prepared from an aqueous slurry of calcined gypsum, paper fibers, a water insoluble organic binder, fiber reinforcement and a set retarder.

Light weight metal fire door core

A flooring composition for mixing with water to produce a self-leveling slurry that quickly hydrates to form a high strength floor underlayment comprising a dry mixture of (1) beta gypsum produced by a continuous method; (2) Class C fly ash; (3) a conventional water reducing aid such as sulfonated melamines, sulfonated naphthalenes and their related formaldehyde condensates, and (4) a conventional set retarder.

Gypsum-based floor underlayment

The present invention describes an improved building material composition, useful for example as a fire door core and to improved methods of making this composition. The building material of the present invention is prepared from an aqueous mixture of expanded perlite and a fast setting, cementitious composition consisting essentially of a hydraulic cement having (1) a Portland cement and (2) a calcium aluminate cement, which composition can be molded and shaped into a fire door core.

Fire door core

Paper and/or mat-faced gypsum board is prepared by applying a relatively thin coating of aqueous gypsum slurry containing a polyvinyl alcohol binder to one or two facer sheets. The polyvinyl alcohol binder provides adequate adhesion between the set gypsum core and the adjacent facer sheet(s) without the need for starch or other conventional binders. In one embodiment, polyvinyl alcohol is concentrated in one or more regions of the core adjacent to the facer sheet(s). In another embodiment, polyvinyl alcohol is applied to an aqueous gypsum slurry used to form the bulk core, such that the polyvinyl alcohol is present throughout the core.

Gypsum board having polyvinyl alcohol binder in interface layer and method for making the same

A method for increasing the drying rate of set plaster by adding fatty alcohol sulfate to the slurry of calcium sulfate hemihydrate from which the plaster is made.

Quick drying plaster

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.

Fire-resistant gypsum fiberboard

Fire-resistant gypsum building materials

Methods of preparing fire doors

A fire resistant article comprising at least about 65 wt. % gypsum dihydrate, reinforcing fibers disposed substantially homogeneously throughout said set gypsum dihydrate, inorganic binder, and optionally refractive filler. This composition provides superior resistance to damage when subjected to a stream of pressurized water as from a fire hose.

Gypsum-containing compositions and fire-resistant articles

A continuous manufacturing line for preparing gypsum fiberboard is provided. The manufacturing line includes equipment for admixing hydratable gypsum, paper, and a quantity of water to form a substantially homogenous slurry, dewatering apparatus for removing a portion of the excess water from the slurry to produce a substantially continuous wet web, pressing equipment for configuring the wet web with a compression means to form a substantially continuous green board, a cutting station for cutting the substantially continuous green board into individual uncured lengths, and a heating station for curing the individual uncured lengths to form gypsum-dihydrate-containing fiberboards.

Growing community of inventors

Lithonia, GA, United States of America

Hubert C Francis