| abstract |
The invention relates to a method comprising: producing a complex including a fibre-based porous back layer, an intermediate layer comprising shredded recycled material, and a porous front layer; placing the complex in a thermoforming mould so as to produce a three-dimensional shell; placing the shell in an RIM mould; and injecting a foam precursor mixture in order to form a sealed acoustic insulation barrier; the binder being incorporated into the front layer, said front layer having a mass per unit area of between 500 and 2000 g/m2, said front layer including at least one lightly compressed, high-absorption region with a thickness of between 4 and 10 mm, the minimum total percentage of the lightly compressed region being 40%. |