| 摘要 |
A rotary welding device has peripheral axial welding bars (pref. heated) so that as e.g. a plastic tube is passed over the welding device the welding bars form transverse welds on the plastic tube to produce a series of sachets. The radial posn. of the welding bars on the welding device is adjustable to vary the distance between consecutive weld lines and so vary the size of the sachets. Several different size sachets can be formed with the same welding device. |
