| 摘要 |
A processing method for easily forming aesthetically excellent ridge and recess portions, etc. in a large region of a synthetic resin tubular body by changing the shape of part of a wall of the tubular body. The method enables to provide a container having decorativeness, appearance, and functionality not having been available. A bottomed tubular mandrel that has a die portion on the outer surface of which at least one of recess-like, ridge-like, and recess/ridge-like shapes partly is formed and has fine through-holes provided in it is inserted into a synthetic resin tubular body while the mandrel is made to be in contact internally with the tubular body. Portion near that portion of the tubular body that faces the die portion is softened by heating. Then, the softened portion is formed to have at least one of the recess portion, ridge portion, and recess/ridge portion on the tubular body. Here, the forming is performed as made by vacuum forming by means of air discharge through an opening end of the mandrel and the fine through- holes. |
