SIZING DIE FOR EXTRUDER AND PREPARATION OF EXTRUSION- MOLDED ARTICLE USING THE SIZING DIE

摘要

PROBLEM TO BE SOLVED: To provide a sizing die for an extruder which can decrease resistance to extrusion and performs a stable molding by the flat molding part of the sizing die and makes dimension and appearance of a pipe-like extrusion-molded article with a small diameter and a thin thickness possible to stabilize and a method for preparing an extrusion-molded article using the sizing die. SOLUTION: An introducing part 12 being brought into contact with a projected cylindrical melt-extrudate Q of a sizing die main body 10 is formed into a curved face part contg. a part of a circle or a composite circle (contg. a tapered face) and at a part before being brought into contact with the curved face part of the introducing part 12, a means 13 for feeding a liq. lubricant W covering the inner wall face of the sizing die 10 is provided. The means 13 for feeding the liq. lubricant is a plurality of jetting holes 14 for jetting a specified pressurized water to the inner wall face 10a of the sizing die main body 10 and a plurality of these jetting holes 14 have a diameter of about 0.7-1.0 mm and are provided at specified intervals in the circumferential direction (in this embodiment for practicing in use, eight holes are provided but the number is not specifically restricted).