Extrusion die and methods of forming

The present invention relates to improved dies for the extrusion of honeycomb structures from plasticized organic or inorganic batch materials. More particularly, the invention relates to a honeycomb extrusion die incorporating a batch stressor which provides improved batch homogeneity, and methods for making and using the die. A batch stressor as defined herein, is a section of a significantly reduced flow channel located virtually immediately upstream of the slot matrix of a die. 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.