摘要:
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.
摘要:
The invention relates to the use of an anti-foaming agent in order to improve the thermal conductivity of screeds The invention also relates to the resulting dry compositions and paste compositions.
摘要:
Dry compositions comprising a hydraulic binder, such as cement or gypsum, and a highly substituted C2-C4 hydroxyalkyl galactomannan with average D-mannosyl to D-galactosyl unit ratio different from 2:1 provide pastes having good water retention characteristics and workability.
摘要:
A joint compound with improved crack resistance is formed by combining water, a filler such as calcium carbonate, a latex emulsion binder, a thickening system such as methyl hydroxyethyl cellulose, and nanocrystalline cellulose. The nanocrystalline cellulose is provided in an amount effective to reduce the crack formation during drying.
摘要:
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.
摘要:
The invention relates to a method for producing a sheet of drywall, comprising the steps of forming a gypsum core from a slurry of plaster of Paris, providing paper or cardboard, producing a sheet of drywall from the gypsum core and the paper or cardboard, wherein the cardboard webs encasing the gypsum slurry absorb water saturated with plaster of Paris from the gypsum slurry and the grains of plaster of Paris in the cardboard are thus converted to calcium sulfate dihydrate in order to form "linker crystals", wherein at the same time calcium sulfate dihydrate from the solution saturated with plaster of Paris crystallizes and wherein the linker crystals that form in the cardboard function as seed crystals.
摘要:
Disclosed is a dry gypsum composition containing hemihydrate gypsum, at least one pigment and a crystal habit modifier. The crystal habit modifier is at least one compound selected from the group consisting of sulfate salts, carboxylate salts, carbonate salts and inorganic chlorides, and a content of the at least one compound is in a range of 0.1 to 5 parts by mass per 100 parts by mass of the hemihydrate gypsum, whereby upon hydration of the hemihydrate gypsum into dihydrate gypsum, the dihydrate gypsum is controlled to become plate crystals having an aspect ratio of 1 to 9. A gypsum-based coating formulation making use of the dry gypsum composition is also disclosed.
摘要:
An aqueous gypsum plaster-cement composition comprises a hydraulic binder consisting of calcined gypsum and hydraulic cement in a weight ratio of from about 4:1 to about 2:1, an aggregate which comprises sand, a foam, a perlite, rice hulls or a mixture thereof, a superplasticizer comprising an air entraining agent, a retarder, and water in an amount of from about 0.4 to about 0.75 parts by weight per part of binder, with the proviso that the gypsum plaster-cement composition contains essentially neither a pozzolana nor lime. The use thereof, a method of constructing buildings using this composition and the buildings obtainable in this way are also described.