| abstract |
Sound absorbing/sound blocking products, including trim products formed from a porous fibrous layer backed by a sound absorbing layer and a sound blocking layer for use within vehicles, and methods of making same, are provided. A porous fibrous layer structure including a fibrous layer backing is heated to achieve a fluid or semi-fluid state and then subjected to vacuum to draw air through the fibrous layer backing to create a porous structure. A layer of sound absorbing and a layer of sound blocking material may be applied to the porous fibrous layer backing to provide improved acoustic properties. An underlayment may further be included to provide selected areas of increased thickness and provide tailoring of sound attenuation. |