Pressed porous filter bodies

A method for making a channeled honeycomb filter preform which comprises the steps of:

• introducing a charge of a plasticized powder batch material into a pressing chamber, the pressing chamber including a sidewall member and at least first and second opposing pressing elements, the pressing elements comprising, respectively, first and second base plates and first and second arrays of channel-forming members attached to and extending perpendicularly from the respective base plates;
• bringing the sidewall member and opposing first and second pressing elements into contact with each other and with the charge of batch material to form a substantially closed pressing chamber wherein:
• (i) the channel-forming members of the first pressing element extend from the first base plate toward the second base plate but are separated by a first space therefrom;
• (ii) the channel-forming members of the second pressing element extend from the second base plate toward the first base plate but are separated by a second space therefrom;
• and
• (iii) the channel-forming members of the first base plate are generally parallel with but laterally offset from the channel-forming members of the second base plate;
• thus to form the charge of batch material into a honeycomb filter preform incorporating opposing, overlapping arrays of channels separated by channel walls of the batch material, each channel having an open end and a closed end, the closed end being bounded by an end segment of the plasticized powder batch material continuous with the channel walls;
• opening the pressing chamber, and
• removing the honeycomb filter preform from the chamber.