Extrusion-molding machine, extrusion-molding method, and method for manufacturing honeycomb structured body

An extrusion-molding method using an extrusion-molding machine provided with a screw having a blade portion for extruding a molding material, the screw disposed in a tightly-closed space, and a die, comprising:

• mixing a wet mixture containing inorganic powder serving as a molding material;
• and at the same time,
• continuously extruding said wet mixture through said die placed at the outlet of said space,
• wherein
• said space is maintained in a reduced-pressure atmosphere, and
• a high-hardness coat layer is formed at least on said blade portion.

A method for manufacturing a honeycomb structured body comprising:

• obtaining a wet mixture containing inorganic powder by wet-mixing;
• extrusion molding the wet mixture for molding thereof to manufacture a pillar-shaped honeycomb molded body having a number of cells, each penetrating in a longitudinal direction, placed in parallel with one another with a cell wall therebetween;
• and
• firing said honeycomb molded body to manufacture a honeycomb structured body made of a honeycomb fired body,
• wherein
• said extrusion-molding is carried out using an extrusion-molding machine comprising a screw having a blade portion for extruding a molding material with a high-hardness coat layer formed at least on said blade portion, the screw disposed in a tightly-closed space, and a die, by mixing said wet mixture while maintaining said space in a reduced-pressure atmosphere, and at the same time continuously extruding said wet mixture through said die placed at the outlet of said space.