A forming device and method for use in a packaging machine of the type where packages are produced from a tube. The forming device comprises two opposing sealing elements between which the tube is arranged to be flat-laid and squeezed to heat the thermoplastic and obtain a first transverse seal of the tube. It further comprises two volume control elements. The forming device is characterized in that it is arranged to displace the first transverse seal off-center in relation a longitudinal axis of the first portion of the tube in a displacement direction essentially perpendicular to the first transverse seal to enable later shaping of a corresponding final package with a wall arranged with a predetermined angle of inclination in relation to the displacement direction. The invention also relates to a machine, a process and a packaging laminate.