The present invention relates to apparatus and methods for thermally treating webs which comprise thermoplastic respectively meltable compounds thereby creating cylindrical or elliptic consolidation regions which may optionally comprise an aperture by employing a thermal energy source such as ultrasonic energy as well as to webs comprising elliptic consolidation regions. In a particular aspect the invention concerns apparatus and methods for creating the consolidation regions by using an anvil with a flexible elongated member such as a wire a chain or a tubular anvil with circumferential ribs.
