Usg Interiors, Inc.

United States Gypsum Company

Mirza A Baig

Mark H Englert

John J Polyner

Terry Couch

William A Schmitt

Rajinder Singh

Michael A Kacner

John C Gaynor

An improved economically produced clean room ceiling tile formed as a composite comprising a base board and a finish coated paper facer laminated to the base board. The base board is preferably made with excess thickness and is machined to a desired caliper. The machined board is sealed with a clay coating and thereafter coated with a water-based adhesive. The paper facer is laminated to the board with the water-based adhesive and is finish coated with a water-based wet scrubbable coating. The paper facer is easy to laminate, exhibits excellent coverage of surface defects in the base board surface, is fully compatible with the water-based finish coating, and contributes to the sag resistance of the tile.

Composite ceiling tile

A ceiling tile of gypsum and cellulose fibers formed into a board by initially mixing the fibers and gypsum in a water-based slurry that is felted and thereafter pressed and dried with a desired board thickness, the dried board being processed to form a plurality of holes in a face thereof through at least the majority of the thickness of the board, the collective volume of the holes being sufficient to reduce the weight of the board by at least 10% and increase the NRC exhibited by the board over that which would otherwise be found in a board of the same composition without such holes.

Ceiling tile construction

A composition and process suitable for making acoustic tiles are disclosed. Certain embodiments of the composition comprise: perlite; inorganic material selected from the group consisting of calcium sulfate, calcium carbonate, clay and mixtures thereof; a binder selected from the group consisting of starch, a combination of starch and cellulosic fibers, latex, kraft paper gel and mixtures thereof; optionally mineral wool; optionally gypsum; and cellulosic fiber, wherein at least a portion of the cellulosic fiber and at least a portion of the inorganic material are pulp and paper processing waste comprising cellulosic fiber, clay and calcium carbonate. Certain embodiments of the process comprise: forming an aqueous slurry; continuously flowing slurry onto a moving foraminous wire to form a cake; dewatering the cake to form a base mat; and drying the base mat.

Acoustic ceiling tiles made with paper processing waste

A ceiling tile product and method in which a slurry formed mat primarily comprising mineral wool and binder is provided with a binder enhancement zone at its face. The binder enhancement zone can reduce the total required latex content, reduce the amount of finish or paint needed to achieve a commercially acceptable color and improve noise reduction.

Ceiling tile with non uniform binder composition

A composite board comprising a core and a paper facer sheet adhesively laminated to one face of the core, the core including a mixture of perlite, binder, and cellulose fiber, the core being formed as a water slurry with said perlite, binder and cellulose fiber being uniformly distributed therein, the perlite being in an expanded state such that its particles include internal voids and exhibit a density of about 5 to about 15 pounds per cubic foot and being present in sufficient quantity to occupy in bulk at least 50% of the volume of the core, on a weight basis, the perlite and cellulose fiber combined forming at least 25% of the weight of the core. The paper facer being laminated to the core with a water-based adhesive applied across substantially the full area of the facer, both the compressive strength of the perlite and tensile strength of the cellulose fiber being utilized by operation of the binder such that a relatively high nail-pull capacity in comparison to the weight of the composite board is achieved and sag resistance is imparted to the composite board when it is used for ceiling tile.

Lightweight panel

An acoustical ceiling tile having an improved sound absorption value and having a dual layer of acoustical materials. The base mat layer has either no mineral wool or a low mineral wool content. The surface layer has a high mineral wool content which provides improved sound absorption values with or without perforating or fissuring the tile. The dual layer acoustical ceiling tile has a noise reduction coefficient (NRC) value of at least about 0.50.

Dual layer acoustical ceiling tile having an improved sound absorption value

A high strength, low density fiber board panel for use in the furniture industry is provided, including mineral wool, a lightweight aggregate material, cellulosic fiber, a binding agent and gypsum. The mineral wool makes up approximately 0% to 33%, the lightweight aggregate material approximately 25% to 41%, the cellulosic fiber approximately 20% to 35%, the binding agent approximately 5% to 9%, and the gypsum approximately 0% to 23%, of the dry solids weight of the panel.

High strength low density board for furniture industry

A lightweight gypsum board is provided, including, by dry weight, gypsum as the largest single ingredient, perlite as the second largest single ingredient, and starch as a minor ingredient, in the board. The starch may be pre-cooked prior to mixing, and is dispersed in the core of the board to act as a binder for binding the gypsum to the perlite. Gypsum board made according to the invention is lighter in weight, yet has a comparable nail pull value to conventional wallboard.

Lightweight gypsum board

A composition suitable for making acoustical tiles in a water-felting process comprises expanded perlite, clay, a binder component selected from the group consisting of starch, latex, cellulosic fiber and mixtures thereof and optionally mineral wool. The use of an expanded perlite having a relatively high density, preferably between about 9 pounds per cubic foot to about 20 pounds per cubic foot, enables the formation of a suitable slurry with a relatively low amount of water and enables a more complete dewatering of the mat prior to drying.

Acoustical tile composition

An acoustical tile composition based on a gypsum/cellulosic fiber composition which can replace all or a portion of the mineral wool normally present in acoustical ceiling tiles. The gypsum/cellulosic fiber composition is combined with a lightweight aggregate material and a binder to form a composition which is used in a water-felting process to manufacture acoustical ceiling tiles and panels. The preferred source of the cellulosic fiber is a composite gypsum/cellulose fiber material which is prepared by mixing the gypsum and cellulosic fiber material with sufficient water to form a dilute slurry which is then heated under pressure to calcine the gypsum, converting it to an alpha calcium sulfate hemihydrate. The resulting composite material comprises cellulosic fibers physically interlocked with calcium sulfate crystals. Another source of both gypsum and cellulosic fibers is waste (scrap) gypsum wallboard. Expanded perlite is the preferred lightweight aggregate material.

Gypsum/cellulosic fiber acoustical tile composition

A mineral wool-free acoustical tile composition and the acoustical tile made therefrom wherein an expanded perlite is used as a substitute for granulated mineral wool to provide porosity and good sound absorption properties. It is preferred that the composition and acoustical tile also contain an inorganic filler to provide texturability during the manufacturing process. In addition, the acoustical tile composition also contains a starch gel binder and a fiber reinforcing agent selected from the group consisting of cellulosic fibers, polymeric fibers and glass fibers. It has been found that the mineral wool-free acoustical tile compositions of this invention have acoustical properties comparable to the commercially available cast mineral wool tiles. In addition, the mineral wool-free compositions can be used to cast an acoustical tile using equipment and procedures currently used to produce cast mineral wool tiles.

Mineral wool-free acoustical tile composition

An improved composite material is produced by mixing gypsum and host particles of a stronger substance, such as wood fibers, in a dilute slurry; heating the slurry, under pressure, to convert the gypsum to calcium sulfate alpha hemihydrate; and substantially dewatering the hot slurry before rehydrating the hemihydrate back to gypsum. The resulting material is a homogoneous mass comprising gypsum crystals physically interlocked with the discrete host particles. According to a further aspect of the invention, an improved wallboard, having fire resistance, dimensional stability and excellent strength properties, is produced by compressing the composite mass before hydrating it to a final set.

Growing community of inventors

Lindenhurst, IL, United States of America

Mirza A Baig