| abstract |
The invention relates to a method comprising: producing a complex including a porous fiber-based backsheet, an intermediate layer comprising fragmented recycled material, and a porous face layer; arranging the complex in a thermoforming mold to produce a three-dimensional shell; arrange the shell in a mold (kidney); and injecting a foam precursor mixture to form a sealed sound insulation barrier; the binder being incorporated into the face layer, said face layer having a mass per unit area of between 500 and 2000 g / m2, said face layer including at least one slightly compressed high absorption region having a thickness of between 4 and 10 mm, the minimum total percentage of the slightly compressed region being 40%. |