Abstract: A honeycomb extrusion die constructed from a strengthening base plate comprising a relatively small number of large feedholes and thin die body plate comprising a larger number of relatively small feed holes supplying extrudable material to a discharge slot array, wherein the two plates are connected by an intermediate compound feed section incorporating branching feed conduits arranged to provide an extrusion path of low flow impedance between the large base plate feed holes and the smaller body plate feed holes.

Abstract: Improved batch uniformity delivered to the discharge slots of an extrusion die is obtained by providing a stressor component of reduced cross-sectional area from the feedholes which suddenly increases the linear flow velocity due to its reduced cross-sectional area, and then just as suddenly restores the original flow conditions as it exits the stressor component into a larger diameter channel. A rapid change in particle alignment, due to the cross-sectional flow change, produces a shearing influence on the batch, and functions to produce a more uniform flow as it enters the discharge slot sections of the extrusion die.

Abstract: A method for forming an extrusion die for producing honeycomb structures having hexagonal shaped cells is disclosed. A plurality of at least three plates are straight cut across the surface portion of each plate with desired angles to produce hexagonal shaped pins. The pins from each of the three plates are successively bonded to a die body or laminated carrier plate, with such orientation and positioning as to produce a die face with hexagonally shaped discharge slots.

Abstract: Apparatus and a method for extruding a honeycomb, providing reductions in curvature or bowing of the extruded honeycomb structure, employs a bow deflector positioned upstream of the extrusion die, the bow deflector comprising adjoining, independently rotatable, first and second aperture plates of tapering thickness, the degree of bow reduction depending on the relative rotational position of the aperture plates and the resulting magnitude of the pressure/flow velocity gradient imparted by the plates on the flow stream entering the die.

Abstract: A honeycomb extrusion die and a method of making the die are disclosed, the die being made by bonding a die discharge section formed as a separate pin array to a separate die body incorporating an array of feed channels, the pin array comprising a plurality of pins attached to and extending outwardly from a body-compatible pin support which is removed after bonding the pins to the body. The pins may be formed of hard wear materials, and may have any of a variety of cross-sectional shapes adapted to improve extrusion uniformity as well as to form honeycomb cells of a variety of different cross-sectional shapes.

Abstract: A honeycomb extrusion die and a method of making the die are disclosed, the die being made by bonding a die discharge section formed as a separate pin array to a separate die body incorporating an array of feed channels, the pin array comprising a plurality of pins attached to and extending outwardly from a body-compatible pin support which is removed after bonding the pins to the body. The pins may be formed of hard wear materials, and may have any of a variety of cross-sectional shapes adapted to improve extrusion uniformity as well as to form honeycomb cells of a variety of different cross-sectional shapes.

Abstract: A honeycomb extrusion die including a feed section having a plurality of feedholes for the input of an extrudable material, a discharge section including a discharge opening for discharging the extrudable material as a channeled honeycomb body, and a multilayer transition section disposed between the feed section and the discharge section for conveying and conditioning the extrudable material from the feed to the discharge sections, is disclosed. Also disclosed are methods for making and using the die.

Abstract: Extrusion die apparatus and an extrusion method for extruding large-cross-section honeycomb structures from plasticized ceramic batch materials are described, the apparatus comprising a die having a support rod connected to its central portion, the support rod being anchored to support means upstream of the die. The support rod and support means act to limit die distortion during extrusion, reducing die strain and stress to levels permitting large honeycomb extrusion without die failure. Dies of optimal thickness are disclosed which reduce the maximum stresses exerted on the die during extrusion.

Abstract: Novel apparatus is disclosed for forming a skin on an extruded honeycomb structure, wherein detrimental distortion of the peripheral cells is eliminated to thus provide a virtually distortion free honeycomb structure with an integral skin. Batch material is supplied for forming the central cellular structure, and a metered flow of skin-forming batch material is transitioned by the apparatus from a predominantly transverse flow to a predominantly longitudinal flow so as to minimize the distortion of web portions of the peripheral cells. In addition the apparatus subjects the skin-forming batch material to a first or primary flow path reduction in the form of flow depth and then, as it is knitting with peripheral web portions of the central cellular structure, the apparatus subjects such batch material to a second or secondary flow path reduction the form of reduced cross-sectional area, so as to effect a complete knitting thereof while still within the extrusion die.

Abstract: A method and apparatus for forming a skin on an extruded honeycomb structure, wherein detrimental distortion of the peripheral cells is eliminated to thus provide a virtually distortion free honeycomb structure with an integral skin. Batch material is supplied for forming the central cellular structure, and a metered flow of skin-forming batch material is transitioned from a predominantly transverse flow to a predominantly longitudinal flow so as to minimize the distortion of web portions of the peripheral cells. In addition, the skin-forming batch material is subjected to a first or primary flow path reduction in the form of flow depth and then, as it is knitting with peripheral web portions of the central cellular structure, it is subjected to a second or secondary flow path reduction in the form of reduced cross-sectional area, so as to effect a complete knitting thereof while still within the extrusion die.

Abstract: Novel method and apparatus for forming a substrate or honeycomb article with multi-cellular densities and/or multi-cellular geometries by positioning a pair of extrusion dies adjacent one another, such that one surrounds the other, and such that discharge slots of one die produce different cellular densities and/or geometries from that of the other. Further, an annular batch reservoir is formed between the mating surfaces of such dies so as to facilitate the flow of batch material from one die to the other, and an integral inner skin is formed between the differing cellular structures.

Abstract: Novel method and apparatus is disclosed for forming an integral skin on an extruded honeycomb structure, wherein the skin material is collected in a peripheral area of a die body, is passed through an adjustable flow control gap, and then through a predetermined gap thickness of a skin forming slot so as to then knit with the honeycomb structure extruded by the die prior to being extruded from the die. A plurality of flow control plates having different internal peripheral diameters are provided so as to provide different flow control gaps, as desired. In addition, a plurality of shims having different thicknesses are provided so as to position the mask a given distance away from the die, and thereby control the skin thickness gap. The die may be formed by merely relieving a peripheral portion of a typically automotive catalytic converter extrusion die and providing a trim ring about the relieved portion so as to inhibit the flow of batch material from partially open feed holes.

Abstract: An improved method of centrifugally separating two differing density phases of a multiphase fluid and simultaneously partitioning the phases with a thixotropic material. The thixotropic material is asymmetrically positioned within a closed end of a tubular container such that the exposed or upper surface of the thixotropic material is contoured to form a space for receiving the multiphase fluid between the surface and a sidewall portion of the closed end of the tube.