a plurality of main pads 11 each for receiving at least a main body 2 on a main holding surface 11s thereof provided along a conveyance circle C about a main rotation shaft 91 and moving along the conveyance circle C following rotation of the main rotation shaft 91 while holding the main body 2 on the main holding surface 11s a pair of side pads 12 provided for each main pad 11 adjacent to the conveyance circle C of the main pad 11 each for receiving at least an end portion of the flap 3 in a girth direction on a sub-holding surface 12s thereof provided along the conveyance circle C.
