| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method that can mold a reduced diameter part and a roughly ring-shaped increased diameter part to a straw for beverage consecutively and easily without requiring complex processing mold and process, moreover only by one processing mold.SOLUTION: A molding mold 2 that comprises: a mold main body 21 in which an edge face in which an insertion hole 21a is bored is formed at a taper shape molding part 21b; and a pin core 22 with a step that is fixed in the mold main body at the same core shape with the insertion hole, and includes a clearance part 23 between an inner peripheral surface 21c of the insertion hole and a fine shank 22a is used, at first, the molding mold 2 heated beforehand or a straw 1 for beverage is moved, one end of the straw 1 for beverage is inserted to the clearance part 23 while being made to contact to the molding part 21b, is pressed until a step part 22b of the molding mold 2 to mold a reduced diameter part 1b, and is pressed by a constant amount further, thereby a roughly ring-shaped increased diameter part 1a is molded near the reduced diameter part 1b of the straw 1 for beverage by the molding part 21b.</p> |
