| 摘要 |
The invention relates to a method comprising: flat-printing a film (1) on one of the surfaces (1a) thereof while leaving an unprinted area (1b) along one of the longitudinal edges (1c) thereof; folding the film (1) such that the unprinted area (1b) of the printed surface (1a) overlaps the opposite edge (1d) of the unprinted surface (1e); and producing a weld (3) at the overlap resulting from the two layers of the film. |
