Abstract: A waveguide for plastic welding has an entry end, an exit end as well as a first and a second inner face arranged between the entry end and the exit end, which are arranged opposite to each other and by means of which laser light can be reflected. A first distance between the entry end and the exit end defines a length of the waveguide and a second distance between the first and the second inner face defines a thickness of the waveguide. The exit end may be arranged opposite to the entry end and a central plane of the waveguide may extend centrally from the entry end to the exit end. The first inner face comprises a continuously curved, concave shape so that a third distance between the first inner face and the central plane varies continuously from the entry end in the direction of the exit end.

Abstract: A vibration welding device has a first tool being with a vibration welding head arranged at a first support, wherein the vibration welding head vibrates in use in a first plane, and the first tool receives a first component, a second tool arranged at a second support, wherein the second tool receives a second component or a stack of welded components. The first and the second support are movable with respect to each other at least along a second axis perpendicular to the first plane from an initial position to a vibration welding position. A clamping arrangement having at least two oppositely arranged clamping devices, each having a clamping surface which is moveable along the first axis between a clamping position and open position, wherein in the clamping position, movement of the second component or the stack of welded components at least along the first axis is hindered during vibration welding.

Abstract: A waveguide for plastic welding has an entry end, an exit end as well as a first and a second inner face arranged between the entry end and the exit end, which are arranged opposite to each other and by means of which laser light can be reflected. A first distance between the entry end and the exit end defines a length of the waveguide and a second distance between the first and the second inner face defines a thickness of the waveguide. The exit end may be arranged opposite to the entry end and a central plane of the waveguide may extend centrally from the entry end to the exit end. The first inner face comprises a continuously curved, concave shape so that a third distance between the first inner face and the central plane varies continuously from the entry end in the direction of the exit end.