US Patent 11891336 Gypsum board containing high absorption paper and related methods

Disclosed are a composite gypsum board and a method of preparing composite gypsum board. The board contains at least one set gypsum layer sandwiched between two cover sheets. The set gypsum layer is formed from at least stucco and water. The stucco material generally includes a high salt impurity content, for example, when the stucco is calcined from certain sources of low-quality synthetic gypsum. For example, in some embodiments, the salts are chloride salts, e.g., sodium chloride (NaCl), potassium chloride (KCl), magnesium chloride (MgCl