New processes and apparatus for forming lap seams and making prefastened disposable absorbent articles are disclosed. The magnets are so arranged that they form a sequence of alternately opposite poles on the surfaces of the rotor directed towards the stator, and the stator comprises two sets of independently supported magnetic yokes located at both sides of the rotor in front of the magnets. The invention is also expressed in a method for processing a payment transaction. The first and fourth splitters are arranged diagonally opposing each other.