US Patent 7638086 Manufacturing method of plugged honeycomb structure

A manufacturing method of a plugged honeycomb structure 30 which comprises a honeycomb substrate 1 and plugging portions 15 arranged so as to form complementary checkered patterns alternately at both end surfaces 11 and 21 of the honeycomb substrate 1. The method comprises attaching mask films 4a and 4b to both end surfaces 11 and 21 of the honeycomb substrate 1, respectively; forming slurry permeation holes 3a at portions of the mask films 4a and 4b corresponding to cell opening end portions 7, respectively; forming deaeration holes 3b at portions of the mask films 4a and 4b facing the portions provided with the slurry permeation holes 3a via cells 2; submerging both end surfaces 11 and 21 of the honeycomb substrate 1 to which the mask films 4a and 4b have been attached into a plugging slurry 6, respectively; and firing the resultant slurry filled substrate 20.