Fire-rated paper faced board having a gypsum core that includes a percentage of recycled waste gypsum material, paper sludge incineration ash, or coal fly ash

摘要

Provided is a fire rated paper faced construction board having a core of set gypsum stucco including recycled waste gypsum material, paper sludge incineration ash and/or coal fly ash. The core has a paper lining and the construction board is made in a continuous ribbon process. In one aspect of the invention the construction board has a density greater than or equal to 1000kg/m3. In another aspect of the invention, the recycled waste materials are present in an amount greater than about 20% by weight.