초록 ▼

A gypsum wallboard, and the method of manufacture, wherein a defoamer is disposed at the gypsum-paper interface during manufacture, causing the foam, present in the core forming gypsum slurry, to break down at the gypsum-paper interface, increasing substantially the density of the gypsum at the inte

A gypsum wallboard, and the method of manufacture, wherein a defoamer is disposed at the gypsum-paper interface during manufacture, causing the foam, present in the core forming gypsum slurry, to break down at the gypsum-paper interface, increasing substantially the density of the gypsum at the interface, relative to the density throughout the center portion of the gypsum core.

대표청구항 ▼

A paper-covered gypsum board having a gypsum core and at least one paper cover sheet adhered thereto, by the setting reaction characteristics of gypsum crystals, said gypsum core having generally therethroughout a great multiplicity of fine foam cells, and a thin layer of set gypsum at the gypsum co

A paper-covered gypsum board having a gypsum core and at least one paper cover sheet adhered thereto, by the setting reaction characteristics of gypsum crystals, said gypsum core having generally therethroughout a great multiplicity of fine foam cells, and a thin layer of set gypsum at the gypsum core-paper interface which has a substantially higher density than said gypsum core, whereby a greater number of gypsum crystals are disposed in interlocking relationship with the paper, by having been formed while in contact with the paper, within interstices thereof, wherein the starch content of the gypsum core is a minor amount of no more than about 2 lbs. per thousand square feet of board per half inch of thickness.