Method for producing ceramic honeycomb filter
A method for producing a ceramic honeycomb filter by blending a starting material mixture comprising a ceramic material, a molding aid and a pore-forming material under a pressure of 0.12-0.5 MPa in a pressure kneader to form a moldable material for a honeycomb extrudate.
1. A method for producing a ceramic honeycomb filter comprising blending a starting material mixture comprising a ceramic material, a molding aid, water and a pore-forming material consisting essentially of microcapsules of a resin shell containing a gas under a pressure of 0.12-0.5 MPa in a pressure kneader to form a moldable material for a honeycomb extrudate;
wherein the molding aid comprises methylcellulose as a binder; and
wherein an amount of the pore-forming material is of from 4-13% by mass.
2. The method for producing a ceramic honeycomb filter according to claim 1 , wherein said moldable material after blending has hardness of 16-23 (measured by a type-C durometer according to JIS K7312).
3. The method for producing a ceramic honeycomb filter according to claim 1 , wherein the blending is conducted in a reduced-pressure atmosphere.
4. The method for producing a ceramic honeycomb filter according to claim 3 , wherein the blending is conducted in a reduced-pressure atmosphere having a vacuum degree of 2×10 −2 MPa or more as a gauge pressure.
5. The method for producing a ceramic honeycomb filter according to claim 1 , wherein the temperature of said moldable material is 15-35° C. during blending.
6. The method for producing a ceramic honeycomb filter according to claim 1 , further comprising the step of extrusion-molding the blended moldable material to a honeycomb shape using a piston-type extruder.