| 摘要 |
The ends of semi rigid plastics tubes, with or without laminated layers of aluminium foil, as used for e.g. toothpaste containers, are sealed by conveying a succession of tube ends projecting vertically from between travelling sponge rubber belts past equipment which in turn (a) between a pair of rotating discs which flatten the ends and imparts a 90 deg. fold to the flattened end, (b) maintains the bent profile until a second set of shaping discs convert the 90 deg. bend to a 180 deg. bend, and (c) applies heat and pressure to weld the folded end back on to its own root before chilling the weld. Pref. ends of the tube are cut off obliquely so extremities blend more neatly against the root of the pinch. |
