Gypsum wallboard and process of making same
AssigneeThe Celotex Corporation
InventorThomas C. Chan
Life of this patent
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Abstract
A process for continuously manufacturing gypsum board having a gypsum core and at least one fibrous cover sheet comprising: (A) applying a defoaming agent to the top surface of the fibrous sheet as it advances along a production line; (B) depositing a foamed gypsum slurry onto the treated surface of the sheet; and (C) forming the composite of the foamed gypsum slurry and fibrous sheet into a gypsum board having a strong bond between the gypsum core and the fibrous cover sheet. The gypsum core-to-fibrous facer bond is highly resistant to failure upon humidification.
Claims18
A process for continuously manufacturing gypsum board having a gypsum core and at least one fibrous cover sheet comprising continuously(a) applying a defoaming agent on the surface of a continuously advancing fibrous sheet, (b) depositing a foamed gypsum slurry onto the treated surface of the sheet, and (c) forming the composite of the foamed gypsum slurry and fibrous sheet into a gypsum board having a strong bond between the gypsum core and the fibrous cover sheet, wherein the slurry contains starch at a concentration of 6 to 13 lbs. per thousand square feet of gypsum board per 1/2 inch of thickness.
Dependencies are inferred from the claim text.