Processes for the manufacture of light-weight inorganic foam materials and articles produced thereby

Abstract

In a process for manufacturing foamed material, particles of a plant material as an organic expansion agent, particles of an inorganic base material and water are blended together. The blend is heated and pressurized to homogenize and liquefy or plasticize it. The blend is then extruded through a die where, in the course of the extrusion, superheated water in the blend vaporizes to foam the blend, the extrudate then being cooled and fired.

What is claimed is: 
     
         1 . A process for manufacturing foamed material comprising blending particles of a plant material as an organic expansion agent, particles of an inorganic base material and water to produce a blend, heating and pressurizing the blend to homogenize and liquefy it, extruding the blend through a die where, in the course of the extrusion, superheated water in the blend vaporizes to foam the blend, and cooling the extrudate. 
     
     
         2 . The process of  claim 1 , the organic plant material including at least one of corn, wheat, rice, potato, apple, and carrot. 
     
     
         3 . The process of  claim 2 , the expansion agent including chopped corn. 
     
     
         4 . The process of  claim 1 , further comprising firing the extrudate to drive off remaining water and organic content in the extrudate. 
     
     
         5 . The process of  claim 4 , further comprising the firing being such as to sinter the inorganic material content of the cooled extrudate. 
     
     
         6 . The process of  claim 4 , further comprising the firing being such as to reaction cure the inorganic material content of the cooled extrudate. 
     
     
         7 . The process of  claim 4 , further comprising cutting the fired extruded, foamed material into lengths for use in producing an article of manufacture. 
     
     
         8 . The process of  claim 4 , wherein the extrudate is injection moulded before firing. 
     
     
         9 . The process of  claim 1 , wherein the plant material is chopped to produce particles up to an eighth of an inch across. 
     
     
         10 . The process of  claim 1 , wherein the expansion agent is present in a weight proportion of between 25% and 50% of the blend weight and the water is present in a weight proportion of between 5% and 10% of the blend weight. 
     
     
         11 . The process of  claim 1 , the base material comprising non-polymeric particles of at least one of mineral, clay, ceramic, cement, concrete and metal. 
     
     
         12 . A foam material manufactured by a process of blending particles of an organic plant material as an expansion agent, particles of an inorganic base material and water to produce a blend, heating and pressurizing the blend to homogenize and liquefy it, extruding the blend through a die where, in the course of the extrusion, superheated water in the blend vaporizes to foam the blend, and cooling the extrudate. 
     
     
         13 . The foam material of  claim 12 , the organic plant material including at least one of corn, wheat, rice, potato, apple, and carrot. 
     
     
         14 . The foam material of  claim 12 , the expansion agent including chopped corn. 
     
     
         15 . The foam material of  claim 12 , the foam material manufactured by a process which further includes firing the extrudate to drive off remaining water and organic content from the extrudate. 
     
     
         16 . The foam material of  claim 15 , the inorganic material content of the cooled extrudate sintered by the firing. 
     
     
         17 . The foam material of  claim 15 , the inorganic material content of the cooled extrudate reaction cured by the firing. 
     
     
         18 . The foam material of  claim 15 , the extrudate being injection moulded before firing.