| 摘要 |
For converting a web of wrapping material from a U-shaped cross section into a tubular shape, an edge guiding mechanism is used having two edge engaging means which may be performed as suction means. Each of the suction means is supported by a pair of guiding rods converging from a forming means and towards a longitudinal welding means. When the suction means are moved along the rods, the suction means are moved towards one another. The suction means provide an engagement with the outer surface of the edges of the web of material and ensure the movement of the edges towards one another and towards the longitudinal welding means so that a web even of a thin and flexible material is securely engaged with the longitudinal welding means. |
