| 摘要 |
PURPOSE:To provide folding lines that are cut in a thermoplastic resin sheet uniformly over the whole surface at a prescribed depth by a method wherein the thermoplastic resin sheet is mounted on a stand with lines which are linear heated bodies projected from the surface at a certain prescribed height. CONSTITUTION:A thermoplastic resin sheet 3 is mounted on a stand 1 in the form of a flat heat-resisting plate with lines that are linear heated bodies 2 projected from the surface at a certain prescribed height. A roll 5 is arranged so that it touches the under surface of the stand with the lines, while a press roll 4 is allowed to touch the surface of the stand. The heating bodies 2 are heated to such an extent that they can soften the resin sheet 3, and simultaneously the rolls 4, 5 are used to let the resin sheet 3 and the stand 1 with the lines move in an arrow direction while depressing them, so that folding lines are formed by making the heated bodies 2 cut into the resin sheet 3. |
