Gypsum plasterboard mix comprising stucco and uncalcined gypsum

摘要

Gypsum plasterboard is produced by combining calium sulphate hemihydrate (stucco) with water to form an aqueous slurry. Uncalcined gypsum having a specific surface area below 0.3 m<2>/g is added to the slurry and the slurry is discharged onto a support so as to form a sheet of gypsum plasterboard. Preferably the uncalcined gypsum is present at 5 to 50 weight % of the calcium sulphate hemihydrate, most preferably at about 20 weight %. The uncalcined gypsum may be synthetic gypsum such as desulphurisation gypsum.