Process For the Production of an Underlay For Roofs

摘要

The invention relates to a method for the production of an active-breathing composite in the form of a web, consisting of a nonwoven made of synthetic material and a layer fully or mainly consisting of polyurethane for utilization as counter ceiling webs for roofs and as façade webs. The invention aims at enabling production of said composite with good properties and greater economic viability. This is achieved in that PU or a mixture of materials with a high fraction of PU is heated to melting temperature and extruded on a nonwoven made of PP in order to form a diffusion-open coating of the PP nonwoven and then pressing the PP nonwoven in order to form an active-breathing composite.