Mat material, exhaust gas purification apparatus, and method for manufacturing exhaust gas purification apparatus

Abstract

A mat material having a generally rectangular shape in a plan view, the mat material including inorganic fibers, wherein the mat material includes a first main surface and a second main surface opposite to each other in a thickness direction, a first end surface and a second end surface opposite to each other in a longitudinal direction that is a winding direction, and a first side surface and a second side surface opposite to each other in a width direction perpendicular to the thickness direction and the longitudinal direction, the mat material includes, on the first end surface, a protrusion designed to protrude toward the second end surface during winding of the mat material, and non-protruding portions provided at both sides of the protrusion in the width direction and designed not to protrude toward the second end surface during winding of the mat material, the mat material includes, on the second end surface, a recess designed to fit the shape of the protrusion on the first end surface during winding of the mat material, and non-recessed portions provided at both sides of the recess in the width direction and designed to fit the shapes of the non-protruding portions on the first end surface during winding of the mat material, and a ratio [D/C] of a length [D] of the non-recessed portion in the width direction to a length [C] of the non-recessed portion in the longitudinal direction is 1.0 or more.

1 . A mat material having a generally rectangular shape in a plan view, the mat material comprising
 inorganic fibers,   wherein the mat material includes a first main surface and a second main surface opposite to each other in a thickness direction, a first end surface and a second end surface opposite to each other in a longitudinal direction that is a winding direction, and a first side surface and a second side surface opposite to each other in a width direction perpendicular to the thickness direction and the longitudinal direction,   the mat material includes, on the first end surface, a protrusion designed to protrude toward the second end surface during winding of the mat material, and non-protruding portions provided at both sides of the protrusion in the width direction and designed not to protrude toward the second end surface during winding of the mat material,   the mat material includes, on the second end surface, a recess designed to fit the shape of the protrusion on the first end surface during winding of the mat material, and non-recessed portions provided at both sides of the recess in the width direction and designed to fit the shapes of the non-protruding portions on the first end surface during winding of the mat material, and   a ratio [D/C] of a length [D] of the non-recessed portion in the width direction to a length [C] of the non-recessed portion in the longitudinal direction is 1.0 or more.   
     
     
         2 . The mat material according to  claim 1 ,
 wherein the mat material is a needle-punched mat.   
     
     
         3 . The mat material according to  claim 2 ,
 wherein the mat material includes multiple entanglement points formed by needling at least one of a front surface or a back surface thereof, and at least one of a 4 mm×4 mm first region without the entanglement points or a 3 mm×8 mm second region without the entanglement points is arranged in a 25 mm×25 mm region.   
     
     
         4 . The mat material according to  claim 2 ,
 wherein the inorganic fibers have an average fiber length of 1 to 150 mm.   
     
     
         5 . The mat material according to  claim 1 ,
 wherein the mat material is a papermaking mat.   
     
     
         6 . The mat material according to  claim 5 ,
 wherein the inorganic fibers have an average fiber length of 200 to 20000 μm.   
     
     
         7 . The mat material according to  claim 1 ,
 wherein an inorganic binder is attached to a surface of each inorganic fiber.   
     
     
         8 . The mat material according to  claim 1 ,
 wherein an organic binder is attached to a surface of each inorganic fiber.   
     
     
         9 . The mat material according to  claim 1 ,
 wherein an inorganic binder and an organic binder are attached to a surface of each inorganic fiber.   
     
     
         10 . The mat material according to  claim 1 , further comprising a polymeric dispersant. 
     
     
         11 . The mat material according to  claim 9 ,
 wherein the inorganic binder and the organic binder are attached in an individually dispersed state to the surface of each inorganic fiber.   
     
     
         12 . The mat material according to  claim 9 ,
 wherein aggregates of the inorganic binder and the organic binder are attached to the surface of each inorganic fiber.   
     
     
         13 . The mat material according to  claim 12 ,
 wherein the surface of each inorganic fiber is at least partially covered with a coating layer containing a mixture of the inorganic binder and the organic binder.   
     
     
         14 . The mat material according to  claim 13 ,
 wherein the coating layer is formed from a continuous flaky mixture of the inorganic binder and the organic binder.   
     
     
         15 . The mat material according to  claim 13 ,
 wherein the coating layer has a stepped shape.   
     
     
         16 . The mat material according to  claim 13 ,
 wherein a particulate mixture of the inorganic binder and the organic binder is attached to a surface of the coating layer.   
     
     
         17 . The mat material according to  claim 1 ,
 wherein a ratio [A/C] of a length [A] of the mat material in the longitudinal direction to the length [C] of the non-recessed portion in the longitudinal direction is 10 or more.   
     
     
         18 . An exhaust gas conversion apparatus comprising:
 a casing;   an exhaust gas treatment unit; and   a mat material between the casing and the exhaust gas treatment unit,   wherein the mat material is the mat material according to  claim 1 .   
     
     
         19 . A method for producing an exhaust gas conversion apparatus, the method comprising
 a press-fitting step of press-fitting an exhaust gas treatment unit having the mat material according to  claim 1  wound therearound into a casing by hard stuffing, pre-calibration, or post-calibration.