Abstract: A method of extruding a honeycomb type structures, such as filters, by flow of extrudable material (e.g. ceramic material) through a die with feed holes having smooth and gradual transition of flow cross sectional area and shape to be congruent at end of holes forming junction with intersections of criss crossing discharge slots. In a typical prior art extrusion die, the feed holes are circular in cross section throughout their length and feed into respective intersecting discharge slot portions. There is an abrupt change in cross section area and shape, from circular to cross shaped, at the entrance to the discharge slots. This construction results in flow inhibiting land portions at the entrance to the discharge slot portions. Such a construction causes bending forces or moments on these flow obstructing entrance portions of the discharge slots and also subjects them to increased abrasive wear whenever the material being extruded contains ceramic or other hard particles.

Abstract: An extrusion die for forming honeycomb type structures, such as filters. In a typical prior art extrusion die, the feed holes are circular in cross section throughout their length and feed into respective intersecting discharge slot portions. There is an abrupt change in cross section area and shape, from circular to cross shaped, at the entrance to the discharge slots. This construction results in flow inhibiting land portions at the entrance to the discharge slot portions. Such a construction causes bending forces or moments on these flow obstructing entrance portions of the discharge slots and also subjects them to increased abrasive wear whenever the material being extruded contains ceramic or other hard particles. By this invention, the feed holes are uniformly tapered from an annular or polygonal transverse cross section at their input ends to a (conventional) cross shape at their outlet ends where by feed the discharge slots.

Abstract: This invention relates to a method for forming a die for use in fabricating a ceramic honeycomb monolith structure having passages separated by walls having predetermined thicknesses. The method involves forming slots in the die and then applying a uniform coating of iron boride, chromium carbide, aluminum oxide, titanium carbide, titanium nitride or titanium carbonitride to the slot-defining surfaces of the die through CVD, the coating ranging in thickness up to 30 microns and being controlled in thickness to .+-.1 micron.

Abstract: The apparatus of the present invention includes a rotatably driven turret carrying one or more collector means at selected radial and angular positions, and transfer means synchronously driven with said turret for depositing on each of said collector means a design configuration. The turret and each of the transfer means share a common point of rotation along respective central axes thereof.