Producing foamed gypsum board using a foaming agent blend
AssigneeUSG Corporation
InventorSteven W. Sucech
Life of this patent
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Abstract
This invention is a process and foaming system for producing foamed gypsum board which permits the production and control of large foam voids in the gypsum core by adjusting the ratio of a first foaming agent and a second foaming agent. My process includes the steps of preforming a first foaming agent which forms stable foam voids in a gypsum slurry and independently preforming a second foaming agent which forms unstable foam voids in a gypsum slurry. Independently, blending the two different foaming agents is the key to controlling void size. A greater amount of the second foaming agent and a lesser amount of the first foaming agent is preferred.
Claims12
A process for producing foamed gypsum board which comprises the steps of:
- providing an aqueous gypsum slurry;
- providing a stream of a preformed first foaming agent which forms stable voids in a gypsum slurry;
- providing a stream of a preformed second foaming agent which forms unstable voids in a gypsum slurry;
- pumping and blending the streams of the first foaming agent and the second foaming agent together to form a blended stream of the foaming agents having a greater amount by weight of the second foaming agent and a lesser amount by weight of the first foaming agent;
- mixing the blended stream of foaming agents with the gypsum slurry to produce a foamed gypsum core wherein the mixing produces a multiplicity of large voids substantially uniformly distributed throughout the foamed gypsum core;
- and
- controlling the production of the large voids by adjusting pump settings to adjust the weight ratio of the first foaming agent to the second foaming agent until desired board core is obtained.
Dependencies are inferred from the claim text.