| 摘要 |
In a process of producing a flattened gusseted continuous tubing (1) from a flat continuous film of synthetic thermoplastic gussets are formed in the flat continuous film and said continuous film is laid in the form of the continuous tubing to be formed in such a manner that the lateral marginal portions of the flat continuous film are superposed adjacent to the outer edge of the covering gusset portion, and the marginal portions are joined by a longitudinally extending seam (8) weld which closes the continuous tubing. That portion of the gusset which covers the still unwelded marginal portions of the continuous film is reversely folded on itself, the marginal portions are subsequently provided with the longitudinal seam weld (8) in a region which in a top plan view is aligned with the outer edge of the covering portion when said gusset portion has not yet been reversely folded, and the reversely folded portion is then backfolded. |
