Method for making an extrusion die for forming helically wound extrudate particles.

摘要

An extrusion die useful for forming helical extrudate particles of inorganic oxide materials, is made by molding the die around pins (34) having helical outer surface (35) to form extrusion holes in the die. Helical walls of the extrusion holes are formed by the helical shape of the pins (34). When the molded die is formed, the helical pins (34) are unscrewed out of the helical holes in the die to avoid damage to the die.