Method for manufacturing honeycomb filter

Abstract

A method for manufacturing a honeycomb filter includes applying a first sealing material paste to a side face of one of honeycomb fired bodies to form a sealing material paste layer thereon. Another of honeycomb fired bodies is laminated on the first sealing material paste layer to manufacture an aggregated body of honeycomb fired bodies. The aggregated body of honeycomb fired bodies is heated so that the first sealing material paste layer is dried and solidified to produce a ceramic block. A second sealing material paste is applied to a peripheral face of the ceramic block in accordance with irregularities formed thereon so that an outer peripheral surface of the honeycomb filter has surface irregularities thereon. The second sealing material paste is dried and solidified to form a sealing material layer on the peripheral face of the ceramic block.

1 . A method for manufacturing a honeycomb filter, said method comprising:
 preparing a wet mixture comprising at least one of silicon carbide and silicon-containing silicon carbide;   extrusion-molding said wet mixture to manufacture honeycomb molded bodies each having a longitudinal direction and a plurality of cell walls extending along the longitudinal direction to define a plurality of cells;   providing a plug material paste in the cells to seal either one of both ends of each of said cells;   firing said sealed honeycomb molded bodies to manufacture a honeycomb fired bodies;   applying a first sealing material paste to a side face of one of said honeycomb fired bodies to form a sealing material paste layer thereon;   laminating another of said honeycomb fired bodies on said first sealing material paste layer to manufacture an aggregated body of honeycomb fired bodies;   heating said aggregated body of honeycomb fired bodies so that said first sealing material paste layer is dried and solidified to produce a ceramic block;   applying a second sealing material paste to a peripheral face of said ceramic block in accordance with irregularities formed thereon so that an outer peripheral surface of the honeycomb filter has surface irregularities thereon; and   drying and solidifying said second sealing material paste to form a sealing material layer on the peripheral face of said ceramic block.   
     
     
         2 . The method for manufacturing a honeycomb filter according to  claim 1 , further comprising:
 cutting the peripheral face of said ceramic block.   
     
     
         3 . The method for manufacturing a honeycomb filter according to  claim 1 , wherein said second sealing material paste has a viscosity lower than a viscosity of said first sealing material paste. 
     
     
         4 . The method for manufacturing a honeycomb filter according to  claim 1 , further comprising:
 passing said ceramic block on which said second sealing material paste is coated through a squeegee having a cylindrical shape so that a coated surface of the ceramic block keeps the irregularities formed on the peripheral face of said ceramic block.   
     
     
         5 . The method for manufacturing a honeycomb filter according to  claim 1 , wherein the cells have exposed cells which are exposed on the peripheral face of said ceramic block, and wherein the exposed cells are not sealed in the filling step. 
     
     
         6 . The method for manufacturing a honeycomb filter according to  claim 1 , wherein a plurality of honeycomb molded bodies having different cross-sectional shapes are manufactured in said extrusion-molding step. 
     
     
         7 . The method for manufacturing a honeycomb filter according to  claim 6 , wherein said plurality of honeycomb molded bodies have a rectangular pillar shape with four side faces and comprises,
 a first honeycomb molded body having one side face with irregularities thereon and two smooth side faces;   a second honeycomb molded body having one side face with irregularities thereon and three smooth side faces; and   a third honeycomb molded body having four smooth side faces.