| 摘要 |
The method comprises a folding step for forming longitudinal folds (20) in a web of flexible film (10) using folding means comprising, for each fold (20), a first and a second idle wheel (22a, 22b), which are arranged offset and substantially parallel to each other on opposite sides of the film (10) and have axes (24) which are orthogonal to the general plane of the film (10), these axes (24) being separated by a distance smaller than the diameter of at least one of the wheels (22a, 22b); and a subsequent step of shaping the folded film (10) into a tubular form. |
