United States Gypsum Company

David R Blackburn

Michael Patrick Shake

Qingxia Liu

John W Wilson

Dennis Mark Lettkeman

Brian Randall

Chris C Lee

Alfred C Li

James Wittbold

Runhai Lu

Ashish Dubey

Brent E Groza

Jeffrey William Donelan

Bruce Lynn Petersen

Richard James Haszel

Sharon Louise Tracy

John L Fall

Yanfei Peng

Yufeng Xu

Eugene Scott Stivender

Peter B Groza

Nicholas McCartney

Stewart E Hinshaw

Rajesh Raitani

Andrew Henry Bauer

James R Wittbold

Sharon L Tracy

Chris Lee

Brian S Randall

Quingxia Liu

A production line and process including a moving carrier web for transporting the panel, and a device for controlling thickness of a formed, but not yet set, fiber reinforced cementitious panel slurry on the web. The thickness control device may include an angled rigid plate for contacting a downstream end of the angled plate with the slurry on the moving carrier web and a mounting stand for mounting the angled rigid. The thickness control device may include a flat horizontal plate at a fixed height over the moving carrier for contacting the entire lower surface of the horizontal plate with a facer on the slurry on the moving carrier web. Or, the thickness control device may include the angled plate and include the horizontal plate that contacts the facer.

Apparatus and process with a vibratory angled plate and/or fixed horizontal plate for forming fiber-reinforced cementitious panels with controlled thickness

Disclosed are hydrophobic finish compositions and cementitious articles made with the hydrophobic finish compositions. In some embodiments, the article is a waterproof gypsum panel surface reinforced with inorganic mineral fibers that face a flexible and hydrophobic cementitious finish possessing beneficial waterproofing properties. These waterproof gypsum panels have many uses, such as, tile backer board in wet or dry areas of buildings, exterior weather barrier panel for use as exterior sheathing, interior wall and ceiling, and roof cover board having water durability and low surface absorption. The flexible and hydrophobic cementitious finish can include fly ash, film-forming polymer, preferably silane compound (e.g., alkyl alkoxysilane), an extended flow time retention agent including either one or more carboxylic acids, salts of carboxylic acids, or mixtures thereof, and other optional additives. Preferably a pre-coated non-woven glass fiber mat is employed to provide the inorganic mineral fibers for the surface reinforcement.

Hydrophobic finish compositions with extended flow time retention and building products made thereof

Disclosed is an improved facer mat for use as a cover sheet for gypsum board. Also disclosed are gypsum boards containing such mat facers on one or both major surfaces of the board (face and back sides when installed), a method of manufacturing such board, and a method of making the mat. The mat can comprise glass, thermoplastic, and/or thermoset fiber. In preferred embodiments, binder is included with the fiber. The mat has outer and inner surfaces. The mat comprises a first region adjacent to the outer surface defined along a horizontal plane of the mat, the first region having a first substantial thickness, and a second region adjacent to the inner surface defined along a horizontal plane of the mat, the second region having a second substantial thickness. The first region has (a) more hydrophilicity than the second region, (b) more wettability than the second region, and/or (c) less density than the second region.

Mat-faced board

A water-resistant gypsum fiber product comprising siloxane and coated with a coating comprising alkali metal organosiliconate is provided. A method of making a gypsum fiber product in which siloxane is cross-linked at the surface of the product is also provided. A fuel-efficient method for making the product and reducing the amount of siloxane dust released is provided as well.

Compositions and methods for water-resistant gypsum fiber products

Effective use of dispersants in wallboard containing foam results from a method where stucco is mixed with a first dispersant and a first quantity of water to form a gypsum slurry. A soap is blended with a second dispersant and a second quantity of water to make a foam. Subsequently, the foam is combined with the slurry. Choice of different first and second dispersants and their relative amounts allows control of the size distribution of the foam bubbles in the slurry and the resulting voids in the gypsum core. Melamine sulfonate condensate and polycarboxylate dispersants are preferred dispersants.

Effective use of melamine sulfonate condensate dispersants in wallboard containing foam

A gypsum slurry is provided that includes calcium sulfate hemihydrate; water; a dispersant component comprising at least one of the following a comb-branched polymer with polyether side chains, naphthalene sulfonate-formaldehyde condensate or melamine sulfonate-formaldehyde condensate; a foaming agent; and a polycondensation component with three polycondensation repeating units. Also provided is a method for making a gypsum slurry with a foaming agent in which the ratio between the dispersant component and the polycondensation component is adjusted to control for the size of foam bubbles in the gypsum slurry. Gypsum products made from the gypsum slurry are provided and methods for making the products are provided as well.

Additives in gypsum slurries and adjusting their proportions

A panel is provided that includes stucco, water and a dispersant component having dispersing properties and comprising a comb-branched polymer with polyether side chains, naphthalene sulfonate-formaldehyde condensate or melamine sulfonate-formaldehyde condensate. A polycondensation component is also included in the slurry that includes three repeating units. A method of making the gypsum panel includes combining stucco, water and a first dosage of a first dispersant to form a slurry, the first. A second dosage of a second dispersant is added to the slurry. Properties of the gypsum slurry are tested and it is formed into a product. The product sets and properties of the product are identified. The first dosage or the second dosage is changed based on the properties of the slurry or product.

Additives in gypsum panels and adjusting their proportions

A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer and a polycarboxylate dispersant. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. A gypsum building panel is made from the gypsum slurry.

Foamed slurry and building panel made therefrom

A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer and a polycarboxylate dispersant. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. In some embodiments, a gypsum building panel is made from the gypsum slurry.

An improved gypsum slurry that includes water, calcium sulfate hemihydrate, a polycarboxylate dispersant and a modifier. The modifier is chemically configured to improve the efficacy of the polycarboxylate dispersant. Preferred modifiers include cement, lime, slaked lime, soda ash, carbonates, silicates and phosphates.

Modifiers for gypsum slurries and method of using them

A gypsum slurry includes water, a hydraulic component including stucco and a polycarboxylate dispersant. The dispersant has two repeating units wherein the first repeating unit is an olefinic unsaturated mono-carboxylic acid repeating unit or an ester or salt, and the second repeating unit is a vinyl or allyl group bound to a polyether by an ether linkage. The slurry can be made into a gypsum panel.

Growing community of inventors

Barrington, IL, United States of America

David R Blackburn