Patent ID: 8263184

Claim:
Process for the production of an actively-breathing composite in the form of a web consisting of a nonwoven made of synthetic material and a layer comprising polyurethane (PU) for utilisation as an underlay for roofs and as a façade web, comprising the steps of heating a product or a layer comprising PU to melting temperature and extruding the heated product or layer onto a nonwoven consisting of polypropylene (PP) in order to form a diffusion-permeable coating of the PP nonwoven, and pressing the heated product or layer to the PP nonwoven to form an actively-breathing composite, and further comprising providing a bonding agent between the product or layer and the nonwoven during the production of the composite, wherein the providing step comprises applying the bonding agent to the nonwoven in a molten state to provide a bonding agent coated nonwoven such that the extruding step applies the heated product or layer onto the bonding agent coated nonwoven.