| 摘要 |
In a tank blowmoulded from thermoplastic, the opposite side walls are provided with tapers which abut against one another in the centre of the tank and are welded in a liquid-tight manner against the abutting surface. At least one of the abutting surfaces (8, 8') is provided with a surrounding depression or with a plurality of depressions (10, 10') extending over partial regions. These depressions extend outwards as far as the vicinity of the abutting edge (14) and, during pressing in during the welding operation, effect a material displacement towards the abutting edge. This leads to an extremely stable, bead-like weld edge between the two tapers (4, 4'). This effect can be further reinforced by pressing the tapers (4, 4') together in such a manner that the wall thickness of the abutting point (6) is smaller than the sum of the wall thicknesses of the two tapers (4, 4') before welding or pressing together. <IMAGE> |
