30 in fig3 the mould openings 31 have the form of core elements with their sides turned against each other it is of course possible to design these openings so that the ends of the formed core elements are turned against each other it is also possible to attach element 30 to steel plate 29 by a releasable adhesive i e an adhesive bond allowing the element 30 to be released intact and without deformation from steel plate 29 preferably a hot melt adhesive element 30 is preferably extending over a large part of the circumference of the mat wheel for example over half the circumference thereof it is of course also possible to let element 30 be extended over the whole circumference but such a long element might be more difficult to handle in order to be easily releasable in the sense of the present disclosure the element 30 shall contain a row of moulds and thereby extend over at least a quarter of the circumference of the mat forming wheel as evident from the description of the apparatus of fig1 the absorbent core elements formed in the moulds can be used in an apparatus in which the formed core elements is superposed on each other in the nip between two mat forming wheels and that the formed core elements shall abut each other immediately before the transfer this can be a problem when very thin core elements shall be superposed on each other since the mat forming wheels often do not have perfectly circular cross sections but a slight ovality if the manufacturing tolerance of the mat forming wheels is for example 2 mm the nip between the mat forming wheels.