Patent ID: 7083691

Claim:
A method for producing an elastic, air-permeable laminate film having an elastomeric intermediate layer disposed between outside cover layers made of non-woven material having a fine fiber structure, comprising the steps of: (a) passing a melt film made of a thermoplastic elastomer to a laminating unit and introducing the melt film in a thermoplasticized state between two webs of non-woven material running into the laminating unit to form a multi-layered material having the melt film as an intermediate layer; (b) cooling the intermediate layer to solidification temperature to produce a laminate having an elastomeric intermediate layer with cover layers made of non-woven material; and (c) subsequently passing the laminate to an ultrasound bonding station wherein the elastomeric intermediate layer is melted to form point bonds and air permeable structures in the elastomeric intermediate layer at discrete melt locations by means of ultrasound while maintaining the fine fiber structure of the non-woven material, the air-permeable structures formed by ultrasound at the melt locations being covered by the fine fiber structure of the cover layers.