Method for preparing uniformly foamed gypsum product with less foam agitation

A method of preparing a foamed gypsum board comprising, continuously and concurrently:

• inserting calcined gypsum and water into a mixing chamber through one or more inlets of the mixing chamber;
• agitating the contents of the mixing chamber to form an aqueous dispersion of the calcined gypsum;
• inserting an aqueous foam into the mixing chamber through an inlet located closer to a discharge outlet of the mixing chamber than the inlet or inlets for the calcined gypsum and water, such that the foam is agitated less than the calcined gypsum to thereby minimize destruction of the foam while uniformly dispersing the foam in the aqueous gypsum dispersion;
• discharging the contents of the mixing chamber through the discharge outlet and depositing the contents onto a moving cover sheet:
• applying a second cover sheet over the deposited contents:
• and
• allowing the resultant assembly to set and dry such that the calcined gypsum forms set gypsum having voids uniformly dispersed therein.

A method of preparing a foamed gypsum board comprising, continuously and concurrently:

• inserting calcined gypsum and water into a mixing chamber through one or more inlets;
• agitating the contents of the mixing chamber to form an aqueous dispersion of the calcined gypsum;
• discharging the contents of the mixing chamber through a discharge outlet into a discharge conduit;
• inserting an aqueous foam through an inlet into the discharge conduit, such that the foam is mildly agitated to thereby minimize destruction of the foam while uniformly dispersing the foam in the aqueous gypsum dispersion;
• discharging the resultant dispersion from the discharge conduit and depositing the dispersion onto a moving cover sheet:
• applying a second cover sheet over the deposited dispersion;
• and
• allowing the resultant assembly to set and dry such that the calcined gypsum forms set gypsum having voids uniformly dispersed therein.

A method of preparing a foamed gypsum board having a hard edge or edges, comprising, continuously and concurrently:

• mixing and agitating calcined gypsum and water to form an aqueous dispersion of the calcined gypsum;
• dividing the aqueous dispersion to form a core stream of the aqueous dispersion and one or more edge streams of the aqueous dispersion;
• mixing an aqueous foam into the core stream, such that the foam is mildly agitated to thereby minimize destruction of the foam while uniformly dispersing the foam in the aqueous dispersion;
• depositing the core stream onto a moving cover sheet;
• depositing the edge stream or streams onto the cover sheet contiguous to one or both edges of the deposited core stream;
• applying a second cover sheet over the deposited streams;
• and
• allowing the resultant assembly to set and dry such that the calcined gypsum forms set gypsum and the set gypsum in the deposited core stream has voids uniformly dispersed therein.