Patent ID: 7101165
Filing Date: 2006-09-05
Classification: B28B,B29C,B29L,C04B

Abstract:
1. 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, wherein said gap is formed in a circumferential direction such that the rear end of each said second lead surface is circumferentially offset from the forward end of each said first lead surface, and wherein a rear end of each said thread of said second lead is disposed substantially in a common plane to a leading end of said thread of said first lead so that said pressing screw portion and said dispersing screw portion are not spaced apart in an axial direction of said screw extruder.