Patent ID: 7163389
Filing Date: 2007-01-16
Classification: B23H,B28B,B29C,B29L,Y10T

Abstract:
1. An extrusion die for honeycomb extrusion molding, comprising: back holes for introducing a raw material to be molded; slits for extruding said raw material; wherein said extrusion die comprises an inside section; an outer peripheral section; and an outermost peripheral section; wherein: all of said slits are formed by grinding a metal body by means of a disk grinding stone and all of said slits having a constant cross-section; a width of the slits disposed in said outer peripheral section is wider than a width of the slits disposed in said inside section; and a surface roughness (Ra) of the slits in said inside section a is 0.1 μm or smaller; and the ratio of slit depths in a said outer peripheral section at each intersection is 10:7 to 10:10, or an absolute value difference of slit depth in said outer peripheral section is smaller than 0.2 mm.