Patent ID: 9464004
Filing Date: 2016-10-11
CPC Classification: B28B,C04B,F27B

Claim Text:
1. A method of manufacturing porous ceramic articles, comprising: a) forming a plurality of extruded green bodies from a ceramic precursor batch composition comprising a particle size distribution (PSD) defined by a mixture of raw materials used to form the ceramic batch precursor composition, wherein a target PSD is determined to results in a firing shrinkage of a porous ceramic article to a target specification dimension, and wherein the PSD changes from the target PSD; b) firing the extruded green bodies in a tunnel kiln comprising a zone through which each of the extruded green bodies pass, wherein the zone is heated to a top soak temperature to produce from each extruded green body a porous ceramic article that undergoes an amount of shrinkage or growth variability during said firing, wherein the amount of shrinkage or growth variability is defined by a shrinkage characteristic, and wherein the porous ceramic article has a porosity, a pore diameter, a coefficient of thermal expansion and a modulus of rupture; c) determining the shrinkage characteristic of at least one sample of the porous ceramic articles formed by said firing wherein the shrinkage characteristic is the amount of shrinkage or growth variability being a dimensional change of the porous ceramic article away from the target specification as caused by the change in the PSD of the ceramic batch precursor composition; and d) wherein, whenever the amount of shrinkage or growth variability as caused by the change in the PSD of the ceramic batch precursor composition is at least 0.2% above or at least 0.2% below the target specification: adjusting the top soak temperature based on the determined shrinkage characteristic to cause a change in the shrinkage characteristic of subsequently formed porous ceramic articles that reduces the amount of shrinkage or growth variability for each porous ceramic article; and e) wherein the adjusting of the top soak temperature includes either: