The honeycomb structure includes a pillar-shaped honeycomb structure body, and a circumferential coating layer disposed to surround a circumference of the honeycomb structure body, and cells which are formed at an outermost circumference of the honeycomb structure body and in which peripheries of the cells are defined by the partition walls without any lacks are defined as outermost circumference complete cells, and in a cross section of the honeycomb structure body which is perpendicular to an extending direction of the cells a minimum distance T (mm) among distances from the outermost circumference complete cells to the surface of the circumferential coating layer and a porosity P (%) of the circumferential coating layer satisfy relations of Equation (1) and Equation (2) as follows:

1.5≧T≧16×(100−P).sup.−1.4; and  Equation (1):

20≦P≦75.  Equation (2):

A particulate trap filter body has asymmetrical channels. The cross-sectional shape of the asymmetrical channel structure includes a combination of hexagonal, square and triangular shapes. The hexagonal channel and the triangular channel act as inlet channel, and the square channel acts as outlet channel. Compared with the traditional symmetrical filter body structure, the inlet channel volume and filter body wall area can be effectively increased by more than 30%, which means that with capturing the same amount of particles, the particle cake layer formed on the wall surface is thinner. The limiting carbon load of the new channel structure is increased by more than 30%, having a very positive effect on reducing the regeneration frequency and prolonging the service life of the trap.

The invention relates to a wall-flow filter, to a method for the production and the use of the filter for reducing harmful exhaust gases of an internal combustion engine. The wall-flow filter was produced by exposing the filter at least twice successively to a powder-gas aerosol.

A particulate filter having a porous ceramic honeycomb structure with a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels. Filtration material deposits are disposed on one or more of the wall surfaces of the honeycomb body. The highly porous deposits provide durable high clean filtration efficiency with small impact on pressure drop through the filter.

The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gastight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al2O3, SiO2, FeO2, TiO2, ZnO2, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.

A pillar shaped honeycomb structure, including: an outer peripheral wall; and a porous partition wall disposed inside the outer peripheral wall, the a porous partition wall defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path, wherein a surface of the porous partition wall in the cells comprise a collecting layer having an average pore diameter lower than that of the porous partition wall; and wherein magnetic particles having a Curie point of 700° C. or higher are provided either or both between the surfaces of the porous partition wall and the collecting layer, and on the collecting layer.

Provided is a particulate filter in which a PM collection rate is stably increased. The particulate filter according to the present invention includes a substrate 10 having a wall flow structure having a porous partition wall 16 that partitions an inlet cell and an outlet cell, and a wash coat layer held on surfaces of internal pores of the partition wall. In addition, average filling rates A, B, and C of the wash coat layer measured for each predetermined pore diameter range in the internal pores satisfy specific relationships. Further, the wash coat layer is formed in a region that occupies 50% or more of a thickness of the partition wall, and an amount of a noble metal catalyst carried by the wash coat layer is 0 g/L or more but 0.2 g/L or less.

In a porous composite, a base material has a honeycomb structure whose inside is partitioned into a plurality of cells. In the plurality of cells, a plurality of first cells whose one ends in the longitudinal direction are sealed, and a plurality of second cells whose other ends in the longitudinal direction are sealed are arranged alternately. A collection layer covers inner surfaces of the plurality of first cells. An overall Sa that is an arithmetical mean height Sa indicating a surface roughness of a surface of the collection layer in the plurality of first cells is greater than or equal to 0.1 μm and less than or equal to 12 μm. An overall mean thickness that is a mean thickness of the collection layer in the plurality of first cells is greater than or equal to 10 μm and less than or equal to 40 μm.

A honeycomb body for exhaust gas aftertreatment, having a multiplicity of stacked layers. Flow channels are formed between the layers, which extend along the axial extent of the honeycomb body and are flowed through in the axial direction. The honeycomb body has first structured layers formed by successive wave peaks and wave valleys. Protuberances in the direction of the wave peaks belonging to a respective layer are formed from adjacently arranged wave valleys of a first structured layer. The adjacently arranged protuberances of a first structured layer form a channel-like structure extending in the circumferential direction in the first structured layer into which a second layer is inserted to be is fixed in the axial direction with respect to the first structured layer.

A method and extrusion die to form a laminar integral skin of a honeycomb structure is provided. The method includes extruding a ceramic precursor batch through a die with feedholes in entry side and slots in exit face of the die to form the honeycomb structure. In a region on the periphery of the die configured to form the cell matrix, a series of concentric slots around the matrix in the exit face of the die are configured to feed skin onto the matrix. Ring sections between concentric slots are angled away from the center and a mask is disposed on top of the periphery producing a channel for extruded skin to meet and bond to extruded matrix. Optionally, slots in the skin-forming ring sections enhance knitting between laminar skin layers.