| 摘要 |
PURPOSE:To enable to obtain a beautiful corner on a fastening part and to contrive prevention of damage, by a method wherein a thin line part is provided on a position above a line running parallel with the edge of a seam by heating and swaging and then both sheetlike materials are piled up into a state wherein the surfaces become the insides. CONSTITUTION:A thin line part 3 is provided in a recessed state by heating and swaging on a position above a line running parallel with the edge 2 of a seam which is slightly inward from the edge 2 of the seam of a sheet 1 made of thermoplastic synthetic-resin. Then two pieces of sheets 1 are piled up into a state wherein the surfaces become the insides and the edges 2 of the seam on one side of both the sheets 1 are welded together through high frequency. Then sheets 1 each are turned down separately in the opposite direction at the thin line part 3 so that the surfaces become the insides. With this construction, even if the sheet is bent in a U-shaped state a beautiful corner can be prepared, it becomes a desirably one from a commadity point of view, a matter that big force acts upon a fastening part does not happen and damage is prevented. |
