Manufacturing method of plugged honeycomb structure

A manufacturing method of a plugged honeycomb structure including a cylindrical honeycomb substrate in which a plurality of cells having two opening end portions are separated by partition walls and formed so as to communicate with both end surfaces of the honeycomb substrate, and plugging portions arranged so as to plug one of the two opening end portions of the cells and form a complementary checkered pattern with one end surface and the other end surface of the honeycomb substrate, the method comprising:

• an attaching step of attaching mask films to both the end surfaces of the honeycomb substrate, respectively;
• a first perforation step of making slurry permeation holes at portions of the mask films corresponding to the one opening end portion of each of the predetermined cells;
• a second perforation step of making deaeration holes having a diameter of 0.02 to 0.8 mm at portions of the mask films facing the portions provided with the slurry permeation holes via the cells;
• a filling step of submerging both the end surfaces of the honeycomb substrate to which the mask films have been attached into a plugging slurry having a viscosity of 0.5 to 2000 Pa·s, respectively, and filling the one opening end portion of each of the predetermined cells with the plugging slurry to obtain a slurry filled substrate;
• and
• a firing step of firing the resultant slurry filled substrate.