Abstract:
This invention provides low dust low density gypsum wallboard products having high total core void volumes, corresponding to low densities in the range of about 10 to 30 pcf. The wallboards have a set gypsum core formed between two substantially parallel cover sheets, the set gypsum core preferably having a total void volume from about 80% to about 92%, and made from a slurry including stucco, pregelatinized starch, and a naphthalenesulfonate dispersant. The combination of the pregelatinized starch and the naphthalenesulfonate dispersant also provides a glue-like effect in binding the set gypsum crystals together. The wallboard formulation, along with small air bubble voids (and water voids) provides dust control during cutting, sawing, routing, snapping, nailing or screwing down, or drilling of the gypsum-containing products. This invention also provides a method of making the low dust low density gypsum products including the introduction of soap foam in an amount sufficient to form a total void volume, including air voids, preferably from about 80% to about 92% in the set gypsum core, corresponding to a set gypsum core density from about 10 pcf to about 30 pcf. The wallboards produced by the method generate significantly less dust during working.
Abstract:
An about ⅝ inch to ¾ inch thick low weight, low density gypsum panel with fire resistance capabilities sufficient to provide a Thermal Insulation Index of at least 17.0 minutes which when subjected to U419 test procedures will not fail for at least 30 minutes and, in selected embodiments, also has outstanding water resistance properties.
Abstract:
This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.
Abstract:
This invention provides low dust low density gypsum wallboard products having high total core void volumes, corresponding to low densities in the range of about 10 to 30 pcf. The wallboards have a set gypsum core formed between two substantially parallel cover sheets, the set gypsum core preferably having a total void volume from about 80% to about 92%, and made from a slurry including stucco, pregelatinized starch, and a naphthalenesulfonate dispersant. The combination of the pregelatinized starch and the naphthalenesulfonate dispersant also provides a glue-like effect in binding the set gypsum crystals together. The wallboard formulation, along with small air bubble voids (and water voids) provides dust control during cutting, sawing, routing, snapping, nailing or screwing down, or drilling of the gypsum-containing products. This invention also provides a method of making the low dust low density gypsum products including the introduction of soap foam in an amount sufficient to form a total void volume, including air voids, preferably from about 80% to about 92% in the set gypsum core, corresponding to a set gypsum core density from about 10 pcf to about 30 pcf. The wallboards produced by the method generate significantly less dust during working.
Abstract:
A reduced weight, reduced density gypsum panel that includes high expansion vermiculite with fire resistance capabilities that are at least comparable to (if not better than) commercial fire rated gypsum panels with a much greater gypsum content, weight and density.
Abstract:
This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.
Abstract:
The invention generally provides gypsum-containing slurries including stucco, naphthalenesulfonate dispersant, and pregelatinized starch. The naphthalenesulfonate dispersant is present in an amount of about 0.1% -3.0% by weight based on the weight of dry stucco. The pregelatinized starch present in an amount of at least about 0.5% by weight up to about 10% by weight of pregelatinized starch by weight based on the weight of dry stucco in the formulation. Other slurry additives can include trimetaphosphate salts, accelerators, binders, paper fiber, glass fiber, and other known ingredients. The invention also comprises the gypsum-containing products made with such slurries, for example, gypsum wallboard, and a method of making gypsum wallboard.
Abstract:
The invention generally provides gypsum-containing slurries including stucco, naphthalenesulfonate dispersant, and pregelatinized starch. The naphthalenesulfonate dispersant is present in an amount of about 0.1%-3.0% by weight based on the weight of dry stucco. The pregelatinized starch is present in an amount of at least about 0.5% by weight up to about 10% by weight of pregelatinized starch by weight based on the weight of dry stucco in the formulation. Other slurry additives can include trimetaphosphate salts, accelerators, binders, paper fiber, glass fiber, and other known ingredients. The invention also comprises the gypsum-containing products made with such slurries, for example, gypsum wallboard, and a method of making gypsum wallboard.
Abstract:
A reduced weight, reduced density gypsum panel that includes high expansion vermiculite with fire resistance capabilities that are at least comparable to (if not better than) commercial fire rated gypsum panels with a much greater gypsum content, weight and density.
Abstract:
An about ⅝ inch to ¾ inch thick low weight, low density gypsum panel with fire resistance capabilities sufficient to provide a Thermal Insulation Index of at least 17.0 minutes which when subjected to U419 test procedures will not fail for at least 30 minutes and, in selected embodiments, also has outstanding water resistance properties.