United States Gypsum Company

Knauf Gips Kg

Annamaria Vilinska

Alfred C Li

Weixin David Song

Yijun Sang

Brian J Christ

Gregg G Diefenbacher

Fredrick T Jones

Bradley W Todd

Te Hua Lau

Iordana Triantafillu

Francis Loiseau

Mario Dupuis

Mark K Hemphill

Blair C Walker

Stephen P Erickson

Jose Luis Carrazco

Angel Arturo Rueda

Jon Cross

Nicholas S Jones

Kevern O Fraser

Rudy A Schermann

Weixin D Song

Disclosed is a composite gypsum board comprising a set gypsum core disposed between face (e.g., Manila) and back (e.g., Newsline) cover sheets. The set gypsum core is formed from a core slurry comprising stucco, water, and optional additives, such as foaming agent, migrating starch, accelerator, retarder, dispersant, etc. A dense layer formed from a dense layer slurry comprising stucco, water, fiber (e.g., paper fiber), and optionally, strength-enhancing starch, is disposed between the core and the face paper. The dense layer slurry contains a greater concentration of fiber, and optionally, strength-enhancing starch, than the core slurry, but the concentration of one or more other additives (e.g., accelerator, retarder, dispersant, or combinations thereof) is lower or the same in the dense slurry as compared with the core slurry. Also disclosed is a method of making board using one board mixer. In embodiments, paper fiber is added to water to form a suspension. The suspension is introduced, while in a non-laminar state, into the dense slurry. Further disclosed is apparatus, such as an extractor and an additive injection system, which can be a part of a cementitious slurry mixing and dispensing assembly.

Board with fiber-reinforced dense layer

A method for making a gypsum board including:

Methods for reclaiming gypsum panels that contain hydrophobic materials and use thereof

Disclosed is a foam modifier, e.g., useful for gypsum or cement slurries. The foam modifier comprises a fatty alcohol that is added to a gypsum or cement slurry that includes foaming agent, such as an alkyl sulfate surfactant. The fatty alcohol can be a C-Cfatty alcohol in some embodiments. The use of such a foam modifier can be used, for example, to stabilize the foam, reduce waste of foaming agent, improve void size control in the final product, and improve the gypsum board manufacturing process.

Foam modifiers for gypsum slurries, methods, and products

Disclosed is a composite gypsum board comprising a board core and a concentrated layer of substantial thickness (e.g., at least about 0.02 inches). The concentrated layer includes a higher weight percentage of an enhancing additive than the hoard core. The board core has a thickness greater than the thickness of the concentrated layer and forms the bulk of the board volume. The concentrated layer has a higher density (e.g., at least about 1.1 times greater) than the density of the board core. Also disclosed is a method of preparing a composite gypsum board.

Composite gypsum board and methods related thereto

Disclosed is a composite gypsum board comprising a board core and a concentrated layer, as well as related methods of preparing board and slurries. The board core and the concentrated layer both are formed from water and stucco. The concentrated layer is designed to have higher density and/or nail pull than the core. The concentrated layer is further formed from a polysaccharide that forms a complex with calcium ions, e.g., an alginate compound such as sodium alginate. In some embodiments, the concentrated layer is formed from an enhancing additive to enhance strength therein, while the core is formed without using enhancing additive or less enhancing additive than used in forming the board core.

Multi-layer gypsum board and related methods and slurries

Disclosed is a method and system for blending a foam modifier with foaming agent on-line, e.g., as may be particularly useful for gypsum or cement slurries. The foam modifier comprises a fatty alcohol that is added to a gypsum or cement slurry that includes foaming agent, such as an alkyl sulfate surfactant. The fatty alcohol can be a C-Cfatty alcohol in some embodiments. The use of such a foam modifier can be used, for example, to stabilize the foam, reduce waste of foaming agent, improve void size control in the final product, and improve the gypsum board manufacturing process.

Method and system for on-line blending of foaming agent with foam modifier for addition to cementitious slurries

Disclosed is a composite gypsum board comprising a board core and a concentrated layer of substantial thickness (e.g., at least about 0.02 inches). The concentrated layer includes a higher weight percentage of an enhancing additive than the board core. The board core has a thickness greater than the thickness of the concentrated layer and forms the bulk of the board volume. The concentrated layer has a higher density (e.g., at least about 1.1 times greater) than the density of the board core. Also disclosed is a method of preparing a composite gypsum board.

A gypsum slurry includes water, a hydraulic component including calcium sulfate hemihydrate and a linear polycarboxylate dispersant. The linear polycarboxylate anionic dispersant includes a first monomeric repeating unit and a second monomeric repeating unit. The first repeating unit of the linear polycarboxylate dispersant is an olefinic unsaturated carboxylic acid repeating unit or salt thereof. The second repeating unit of the linear polycarboxylate dispersant is a vinyl sulfonate. The slurry can be made into a gypsum panel. Methods of making gypsum slurry and a gypsum panel are also disclosed.

Gypsum slurries with linear polycarboxylate dispersants

Disclosed is a method and system for blending a foam modifier with foaming agent online, e.g., as may be particularly useful for gypsum or cement slurries. The foam modifier comprises a fatty alcohol that is added to a gypsum or cement slurry that includes foaming agent, such as an alkyl sulfate surfactant. The fatty alcohol can be a C-Cfatty alcohol in some embodiments. The use of such a foam modifier can be used, for example, to stabilize the foam, reduce waste of foaming agent, improve void size control in the final product, and improve the gypsum board manufacturing process.

Disclosed is a composite gypsum board comprising a hoard core and a concentrated layer of substantial thickness (e.g., at least about 0.02 inches). The concentrated layer includes a higher weight percentage of an enhancing additive than the board core. The board core has a thickness greater than the thickness of the concentrated layer and forms the bulk of the board volume. The concentrated layer has a higher density (e.g., at least about 1.1 times greater) than the density of the board core. Also disclosed is a method of preparing a composite gypsum board.

Growing community of inventors

Chicago, IL, United States of America

Annamaria Vilinska