摘要 |
The method and apparatus are applicable in production of cans, bottles and more. It has enhanced weld quality, improved appearance and low waste. Laminated foil 2 moves with relatively constant speed and is formed around the mandrel 1. Over the foil edge 7 is placed compressing/cooling bar 10 having cooling channel 11, and over second edge 8 - compressing/cooling bar 12 having cooling channel 13. The profile of mandrel 1 in the heating area of overlapped edges 7 and 8 of foil 2 has step 5 to form cavity 6 between edges 7 and 8. The heating unit 3 is a nozzle supplying hot air into cavity 6. Melting of the foil 2 is limited only to the area, which is not in contact with compressing/cooling bars 10 and 12 and the mandrel 1. During further movement of foil 2 due to change in profile of mandrel 1, transforming into plane 9 the end 8 is lifted up while pressed the end 7 and the two together in compressing/cooling bar 10. After welding area there is cutter 4 to cut the tube into tubular bodies.? |