Patent ID: 7611560

Claim:
A method of manufacturing a plugged honeycomb structure, the plugged honeycomb structure comprising: a cylindrical honeycomb structure having a first end, a second end that is opposite to the first end, porous partition walls and a plurality of cells partitioned by the partition walls, the partition walls and the cells extending through the cylindrical honeycomb structure from the first end to the second end, and plugging members which plug portions of predetermined cells in such a way that the predetermined cells are plugged only at the first end and not plugged at the second end, the remaining cells are not plugged at any position between the first and the second end, the plugging members having a predetermined length from the first end of each of the predetermined cells, wherein the plugged honeycomb structure is in a casing inside an exhaust structure, the method comprising the steps of: forming a clay including a forming material into a honeycomb shape to obtain a cylindrical honeycomb formed body having a plurality of partitioned cells extending through the formed body from the first end to the second end; preparing a plugging material of the plugging members so that a contraction ratio (firing contraction ratio) of the plugging material during firing is a predetermined ratio with respect to the firing contraction ratio of the honeycomb formed body; plugging openings of the predetermined cells of the resultant honeycomb formed body only at the first end with the plugging material to obtain a plugged honeycomb formed body; and firing the resultant plugged honeycomb formed body in a state in which the plugged honeycomb formed body is laid on a firing setter so as to bring the first end plugged with the plugging material into contact with the firing setter to thereby obtain the plugged honeycomb structure.