Extrusion dies

A honeycomb extrusion die, comprising:

• a die body comprising:
• an inlet face;
• an exit face;
• a plurality of pins disposed on the exit face and arranged to define a matrix of intersecting slots, the intersecting slots comprising wide slots and narrow slots formed between the wide slots, wherein the wide slots have a wide slot exit width greater than a narrow slot exit width of the narrow slots;
• and
• feedholes at the inlet face and intersecting with inlet portions to at least one of the wide slots and the narrow slots;
• wherein at least some of the pins that define the wide slots comprise a first surface indentation feature that is (i) located between the respective inlet portion and the respective wide slot exit of the respective wide slot and (ii) spaced away from the wide slot exit;
• wherein at least some of the pins that define the narrow slots comprise a second surface indentation feature that is (i) located between the respective inlet portion and a narrow slot exit of the respective narrow slot and (ii) spaced away from the narrow slot exit;
• and
• wherein the matrix of intersecting wide slots and narrow slots form at least one enclosure of respective wide slots enclosing at least one respective narrow slot,
• wherein one or more respective wide slots comprise a first portion extending between the respective wide slot exit and the respective first surface indentation feature and a second portion extending between the respective inlet portion of the respective wide slot and the respective first surface indentation feature, wherein a width of the first portion is greater than a width of the second portion.

An extrusion apparatus comprising:

• a honeycomb extrusion die, comprising:
• a die body comprising:
• an inlet face;
• an exit face;
• a plurality of pins disposed on the exit face and arranged to define a matrix of intersecting slots, the intersecting slots comprising wide slots and narrow slots formed between the wide slots, wherein the wide slots have a wide slot exit width greater than a narrow slot exit width of the narrow slots;
• feedholes at the inlet face and intersecting with inlet portions to at least one of the wide slots and the narrow slots;
• an impedance plate disposed adjacent to the inlet face of the die body, wherein the impedance plate comprises:
• an entrance face,
• an exit face, and
• entrance openings in the entrance face extending through the impedance plate to the exit face to form a plurality of impedance holes, wherein at least one respective impedance hole corresponds to at least one respective feedhole in the die body,
• wherein at least some of the pins that define the wide slots comprise a first surface indentation feature that is (i) located between the respective inlet portion and a wide slot exit of the respective wide slot and (ii) spaced away from the wide slot exit;
• wherein at least some of the pins that define the narrow slots comprise a second surface indentation feature that is (i) located between the respective inlet portion and a narrow slot exit of the respective narrow slot and (ii) spaced away from the narrow slot exit;
• and
• wherein one or more respective wide slots comprise a first portion extending between the respective wide slot exit and the respective first surface indentation feature and a second portion extending between the respective inlet portion of the respective wide slot and the respective first surface indentation feature, wherein a width of the first portion is greater than a width of the second portion.