摘要:
The invention provides gypsum wallboard, made from gypsum-containing slurries having outstanding hydration rate characteristics comprising alpha-hemihydrate ground to a particular particle size distribution range and having a Blaine surface area in the range from about 3100 cm2/g to about 9000 cm2/g, alone or in combination with beta-hemihydrate.
摘要:
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.
摘要:
The invention provides in one embodiment a gypsum-containing slurry including stucco and an aqueous pre-dispersion of a pregelatinized starch. Also provided is a method of making gypsum wallboard by providing a pre-dispersion of the pregelatinized starch in water, and adding the pregelatinized starch pre-dispersion to the gypsum-containing slurry. The pregelatinized starch can have a particle size distribution within the following range: d (0.1)=about 20μ-35μ, d (0.5)=about 60μ-110μ, d (0.9)=about 100μ-220μ.
摘要:
The invention provides a light weight composite gypsum board including a foamed low density set gypsum core, a top non-foamed (or reduced-foamed) bonding high density layer and a bottom non-foamed (or reduced-foamed) bonding high density layer, a top cover sheet bonded to the foamed low density set gypsum core by the top non-foamed (or reduced-foamed) bonding high density layer, and a bottom cover sheet bonded to the foamed low density set gypsum core by the bottom non-foamed (or reduced-foamed) bonding high density layer. The foamed low density set gypsum core is prepared having a density of less than about 30 pcf using soap foam in the gypsum-containing slurry. The combination of components provide a composite gypsum board having light weight and high strength.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
The invention provides gypsum wallboard, made from gypsum-containing slurries having outstanding hydration rate characteristics comprising alpha-hemihydrate ground to a particular particle size distribution range and having a Blaine surface area in the range from about 3100 cm2/g to about 9000 cm2/g, alone or in combination with beta-hemihydrate.