METHOD FOR EXTRUSION MOLDING AND EXTRUSION MOLDING MACHINE

摘要

PROBLEM TO BE SOLVED: To manufacture a base tube having a high roundness. SOLUTION: This extrusion molding machine having a mandrel 24 in a container 20 so that a section of an extruded material becomes an annular shape comprises a receiving mold 8 detachably mounted at an outlet for extruding a material and formed with a recess made of a smoothly curved surface capable of filling the extruded material at a site opposed to the outlet, a high pressure fluid supply means 42 capable of supplying higher pressure fluid than at least an atmospheric pressure, and a channel 24a for coupling the means 42 to a front end of the mandrel 24 to introduce the fluid from the means 42 to a hollow part of the extruded material.