| 摘要 |
A method for forming a flat foil web (2) into a foil tube (3), wherein the foil web is led, via a collar (4) surrounding a virtual tube (5), to a gap (12) formed by edges (13,14) of said collar. First and second longitudinal sides (22,23) of the flat foil web are made to overlap by means of said gap. The gap extends helically over the virtual tube. Part (24) of the first longitudinal side (22) of the foil web is led to an outer side of the collar remote from the central axis (15) by means of edges (13,14) bounding the gap, whilst the second longitudinal side (23) of the foil web is placed into abutment with the first longitudinal side (22) on an inner side of the collar facing towards the central axis. Following that, the part (24) of the first longitudinal side (22) located on the outer side of the collar is gradually moved towards the inner side of the collar, until said part of the first longitudinal side abuts against the second longitudinal side (23). |
