Patent ID: 8137637

Claim:
A wall flow particulate filter comprising: a first honeycomb substrate having an inlet face, an outlet face, and a plurality of channels extending therebetween; a second honeycomb substrate having an inlet face, an outlet face, and a plurality of channels extending therebetween; wherein the first substrate and the second substrate are different in at least one of porosity, median pore size, and pore size distribution; wherein the outlet face of the first substrate is positioned against the inlet face of the second substrate such that the channels of the first substrate are aligned with the channels of the second substrate to form continuous channels extending from the inlet face of the first substrate to the outlet face of the second substrate, and wherein a portion of the continuous channels are selectively plugged at the inlet face of the first substrate and another portion of the channels are selectively plugged at the outlet face of the second substrate; and a continuous skin joined to each of the first substrate and the second substrate to join the first substrate and the second substrate as a single unit.