RULED LINE FOR FOLDING AND ITS SETTING

摘要

PROBLEM TO BE SOLVED: To enable folding properties and durability to be improved simultaneously. SOLUTION: A thickness t2 of a ruled line 20 is set 0.3-0.9 times the thickness of a synthetic resin sheet 11 and the width (W) is set to 5 times or more the thickness t2. The ruled line 20 is set by thermally molding the sheet 11. Consequently, the thickness t2 larger than when the ruled line 20 is set by a conventional method is maintained, and the width (W) is maintained to be larger than when the line 20 is set by the conventional method. Therefore, it is possible to inhibit a fracture in the ruled line 20 part and improve the durability. Further, the folding properties are also dependable and the ruled line 20 with a large width (W) which a conventional Thompson blade cannot set can be surely set as the ruled line 20 is set by thermally molding it.