Coil shaped pure nickel pipe manufacturing method for liquid crystal back light, involves reducing outer diameter of annealed pipe and winding pipe into coil shaped pipe

摘要

A face portion of a coil shaped pipe (7) which has a predetermined outer diameter and thickness after molding belt material is welded. The pipe is heated to 650-750[deg] C by continuously reducing atmosphere temperature. The outer diameter of the annealed pipe inside the die of a coil extracting machine is made small and the pipe is finally wounded to a coil shaped pipe.