Patent ID: 8551272

Claim:
Method for producing a ceramic filter body ( 1 ) for filtering an exhaust gas stream ( 2 ) of a diesel engine, wherein the filter body ( 1 ) has planar and porous filter sections ( 3 ) that are designed for flow-through of the exhaust gas stream ( 2 ) in a direction transverse to the face of the filter sections ( 3 ), comprising the following method steps: a planar permeable fiber web ( 4 , 4 ′) of filter paper is first impregnated with finely ground ceramic material ( 6 ) under formation of at least one non-impregnated section ( 12 ); wherein a first fiber web ( 4 ) of said planar permeable fiber web ( 4 , 4 ′) is formed into an undulated structure and a second fiber web ( 4 ′) is produced to be flat; wherein at least one individual section ( 12 ) of the fiber web is excluded from impregnation for later formation of an opening ( 13 ) in the filter body ( 1 ); the only partially ceramic-impregnated fiber web ( 4 , 4 ′) is subsequently brought into the shape of a blank of the filter body ( 1 ) in such a way that the impregnated areas of the fiber web ( 4 , 4 ′) assume the shape of the filter body ( 1 ); wherein said first and second fiber webs ( 4 , 4 ′) are connected to one another along several contact lines ( 19 ) at wave peaks of the undulated structure by an adhesive or by said ceramic material ( 6 ); wherein said connected two fiber webs ( 4 , 4 ′) form gas passages ( 18 ) therebetween; the fiber web ( 4 , 4 ′) impregnated with the ceramic material ( 6 ) and shaped is subsequently sintered under heat in such a way that the fibers ( 5 ) of the fiber web are burned off and the ceramic material ( 6 ) is sintered under formation of the filter body ( 1 ) with filter sections ( 3 ) that are continuously porous and gas-permeable between their two faces ( 7 , 8 ); wherein said at least one individual section ( 12 ) of permeable fiber web ( 4 , 4 ′) lacking any impregation is removed from said filter body by burning off said at least one individual section in said sintering, said at least one burned off individual section forming an opening ( 13 ) in the filter body ( 1 ), said opening interconnecting two of said gas passages.