Abstract: A method for forming a ceramic precursor material for use in extruding ceramic honeycomb green bodies is provided. First, a plurality of dry particulate ceramic precursor ingredients are mixed to achieve an initial particulate precursor mixture. This mixture includes a percentage of particles and agglomerates with the agglomerates exhibiting a size greater than the threshold size. Following mixing, the agglomerates in the initial particulate mixture are pulverized to reduce a maximum size of at least some of the agglomerates below the threshold size to form pulverized agglomerates. Finally, a portion of the ceramic precursor ingredients are separated from the initial mixture with that portion comprising at least some of the pulverized agglomerates and at least some of the particles. The method is particularly adapted for use in the fabrication of ceramic honeycomb green bodies having thin webs between 2 and 5 mils in thickness.

Abstract: The present invention provides honeycomb ceramic articles and methods of manufacturing such articles having few or no defects in the outer skin. Methods for minimizing and/or eliminating cracks in thin-wall and ultra-thin-wall cordierite honeycomb articles are disclosed. Advantageously, the present invention prevents skin cracks from forming during the production of thin-wall and ultra-thin-wall cordierite honeycomb articles by optimizing skin properties such as porosity, thickness and pore size distribution.

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: A twin-screw extruder includes a barrel including a pair of chambers in communication with each other and a discharge port, and an extrusion molding die coupled with respect to the discharge port of the barrel. First and second screw sets are rotatably mounted at least partially within respective ones of the pair of chambers. The first and second screw sets each include a raker blade segment at the discharge port of the barrel that includes at least one flight element with a plurality of serrations extending therethrough. Each of the first and second screw sets also include a lobed kneading segment at the discharge port of the barrel that includes at least one flight element. One of the raker blade segment and the lobed kneading segment is located downstream from another of the raker blade segment and lobed kneading segment. A method of using the twin-screw extruder is also provided.

Abstract: A method of manufacturing a honeycomb structure is disclosed wherein a green honeycomb body having a first contour is differentially altered such that the green honeycomb body has a second contour which is wider at a first end than at a second end. In one aspect, the altering is accomplished by removing a part of the green honeycomb body, such as with a removal tool. In another aspect, the altering is accomplished by exposing different regions of the honeycomb body to different drying environments.

Abstract: The present invention provides honeycomb ceramic articles and methods of manufacturing such articles having few or no defects in the outer skin. Methods for minimizing and/or eliminating cracks in thin-wall and ultra-thin-wall cordierite honeycomb articles are disclosed. Advantageously, the present invention prevents skin cracks from forming during the production of thin-wall and ultra-thin-wall cordierite honeycomb articles by optimizing skin properties such as porosity, thickness and pore size distribution.