Extrusion molding apparatus for ceramic molded product

An extrusion molding apparatus for a ceramic molded product, comprising a shaping die for producing a ceramic molded product and a screw extruder having built therein an extruding screw for mixing and leading a ceramic material forward,

• wherein said extruding screw includes a pressing screw portion for pressing said ceramic material toward said shaping die and a dispersing screw portion arranged on the same axis as said pressing screw portion adjacently to the forward end of said pressing screw portion,
• wherein said pressing screw portion assumes the shape of a ridge spirally formed in an axial direction and includes at least one thread of a first lead having a first lead surface facing forward,
• wherein said dispersing screw portion assumes the shape of a ridge spirally formed in an axial direction and includes at least one thread of a second lead having a second lead surface facing forward,
• wherein a gap is formed in a peripheral direction between the rear ends of all of said second lead surfaces at the rear end of said dispersing screw portion and the forward end of said first lead surface at said forward end of said pressing screw portion, and
• wherein said shaping die is for producing a ceramic molded product having a honeycombed structure in which partitioning walls forming a multiplicity of cells communicating through in an axial direction are arranged in the form of honeycomb, and the thickness of said partitioning walls of said ceramic molded product is not larger than 100 μm.

An extrusion molding apparatus for a ceramic molded product, comprising a shaping die for producing a ceramic molded product and a screw extruder having built therein an extruding screw for mixing and leading a ceramic material forward,

• wherein said extruding screw includes a pressing screw portion for pressing said ceramic material toward said shaping die and a dispersing screw portion arranged on the same axis as said pressing screw portion adjacently to the forward end of said pressing screw portion,
• wherein said pressing screw portion assumes the shape of a ridge spirally formed in an axial direction and includes at least one thread of a first lead having a first lead surface facing forward,
• wherein said dispersing screw portion assumes the shape of a ridge spirally formed in an axial direction and includes at least one thread of a second lead having a second lead surface facing forward,
• wherein a gap is formed in a peripheral direction between the rear ends of all of said second lead surfaces at the rear end of said dispersing screw portion and the forward end of said first lead surface at said forward end of said pressing screw portion, and
• wherein said shaping die is for producing a sheet-like ceramic molded product, and the thickness of said partitioning walls of said ceramic molded product is not larger than 100 μm.