Abstract: The invention is directed to a method for managing pore size distribution in honeycomb substrates by using two or more pore forming agents in the batch ingredients. In particular, the invention is particularly useful in managing pore size distribution in cordierite and aluminum titanate honeycomb substrates in the face of particle size variations in the pore forming agents and other materials used to make such substrates.

Abstract: The invention is directed to a method for managing pore size distribution in honeycomb substrates by using two or more pore forming agents in the batch ingredients. In particular, the invention is particularly useful in managing pore size distribution in cordierite and aluminum titanate honeycomb substrates in the face of particle size variations in the pore forming agents and other materials used to make such substrates.

Abstract: Disclosed are porous ceramic honeycomb articles, such as filters, which are composed predominately of a cordierite composition. The ceramic honeycomb articles possess a porous microstructure characterized by a unique combination of relatively high porosity (>45%), and moderately narrow pore size distribution wherein greater than 15% and less than 38% of the total porosity exhibits a pore diameter less than 10 ?m, and low CTE wherein CTE?6.0×10?7/° C. (from 23° C. to 800° C.). The articles exhibit high thermal durability and high filtration efficiency coupled with low pressure drop. Such ceramic articles are particularly well suited for use in filtration applications, such as in diesel exhaust filters. Also disclosed are methods for manufacturing the porous ceramic honeycomb article.

Abstract: Honeycomb shapes are extruded from plasticized ceramic powder mixtures by methods that include reducing the core temperature of the charge of the plasticized mixture during transit through the extruder, such methods being carried out utilizing apparatus comprising twin-screw extruders incorporating actively cooled screw elements, whereby temperature-conditioned charges of plasticized material that exhibit reduced core-to-periphery temperature differentials are delivered for extrusion.

Abstract: Disclosed are porous ceramic honeycomb articles, such as filters, which are composed predominately of a cordierite composition. The ceramic honeycomb articles possess a porous microstructure characterized by a unique combination of relatively high porosity (>45%), and moderately narrow pore size distribution wherein greater than 15% and less than 38% of the total porosity exhibits a pore diameter less than 10 ?m, and low CTE wherein CTE?6.0×10?7/° C. (from 23° C. to 800° C.). The articles exhibit high thermal durability and high filtration efficiency coupled with low pressure drop. Such ceramic articles are particularly well suited for use in filtration applications, such as in diesel exhaust filters. Also disclosed are methods for manufacturing the porous ceramic honeycomb article.