A method for forming an undergarment comprises providing a web, cutting the web to form a pre-form, the pre-form comprising the first and the second transverse edges and two longitudinal edges, each longitudinal edge having two waist sections and a crotch section located intermediate the waist sections, a sealing area being located adjacent and inboard of each waist section, and transferring the pre-form to a processing wheel. The method further comprises gripping the pre-form adjacent each waist section with the grippers in four gripping areas, each gripping area being located near a respective sealing area, jointly rotating at least the grippers that hold the gripping areas in the region of one of the transverse edges around at least one hinging axis extending substantially parallel to the transverse edges of the pre-form to place the transverse edge generally parallel and opposite to the second transverse edge, superimposing the sealing areas in a contacting relationship, joining the superimposed sealing areas, thus forming the undergarment, and releasing the undergarment from the grippers.