The present invention relates to an anvil (402) of an ultrasonic sealing
system (200) for sealing a transversal sealing section (302) of a tube (112) of packaging material. The transversal sealing section (302) comprises a first transversal edge section (304), a longitudinal sealing (LS) section (306) and a second transversal edge section (308), said anvil (402) comprising: a
ridge (410) extending along a first axis (A1) of the anvil (402), a release surface (414) extending along the first axis of the anvil (402), and a
support surface (412) extending along the first axis of the anvil (402) and arranged between the
ridge (410) and the release surface (414), wherein the anvil (402) comprises a first and a second side section (420, 428), a middle section (424), a first transition section (422) arranged between the first side section (420) and the middle section (424), and a second transition section (426) arranged between the middle section (424) and the second side section (428), wherein, in the first and second side section (420, 428), the
ridge (410), the release surface (414) and the
support surface (412) follows a first profile (416), wherein, in the middle section (424), the ridge (410), the release surface (414) and the
support surface (412) follows a second profile (418), wherein a height of the ridge (410) and the support surface (412) in the first profile (416) is greater than a respective height in the second profile (418), and a height of the release surface (414) in the first profile (416) is the same as in the second profile (418).