摘要 |
A rotation-symmetric ultrasound horn for producing a circular seal to effect liquid-tight joining together of, for example, packaging container parts. The ultrasound horn is connected to an ultrasound source which supplies the horn axially via a supply end. The horn displays an opposing, tubular working end with a circular work surface. The mean diameter of the tubular part varies along the axis of the horn so that the horn, in the region of the work surface, is of greater mean diameter and cross-sectional area than in a region located between the work surface and the supply end of the horn. As a result of this design and construction, the initially axial ultrasound waves are given a radial component of sufficient amplitude to achieve welding of thermoplastic material along the circular work surface of the horn. |