Abstract: A multilayer gypsum board forming device, and a gypsum additive delivery system in which additives are delivered to one or more layers of a multi layered gypsum board panels, including engineered polymers, includes at least one additive assembly connected in-line with a first gypsum delivery receptacle for providing an additive fluid feed into the stream of a first gypsum slurry being transported through said first gypsum delivery receptacle for homogenously adding an additive to the first gypsum slurry, and a second gypsum delivery receptacle transporting a second gypsum slurry, in fluid communication with the mixer providing the first gypsum slurry, having a different set of characteristics from those of the first gypsum slurry. At least one outer surface including a polymeric compound or wax emulsion additive entrained therein essentially encases the core gypsum within two facing layers.

Abstract: A method of manufacture of multilayer gypsum board, and a gypsum additive delivery system, including wet gypsum board passing through a board forming station in which additives are delivered to one or more layers of a multi layered gypsum board panels, such as engineered polymers, providing a better and more water resistance surface. Preferably, the gypsum board has a first layer of a mixture of set gypsum having an outer surface and a polymeric compound or wax emulsion additive entrained therein and impregnated in a thin sheet of randomly aligned inorganic fibers to essentially encase the core gypsum within two facing layers.