A honeycombed structure is extruded and wash coat applied to the interior channels of the structure before the honeycomb structure is separated from the die in which it is formed. This method produces the honeycombed structure using a die that includes a die body having an inlet and an outlet side, a...http://www.google.com.hk/patents/US4884960?utm_source=gb-gplus-share專利 US4884960 - Die for extruding and wash coating
