Sound absorbing/sound blocking automotive trim products
View Patent ↗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.
1. A trim product, comprising:
a first composite and a second composite in contacting relationship therewith; wherein said first composite comprises a fibrous primary layer, wherein the fibrous primary layer comprises a layer of fibrous material having opposite first and second sides and fibers that extend from the first side and a secondary layer of thermoplastic material which penetrates said primary layer to form a backing layer having first and second sides and a plurality of air channels formed in the backing layer that extend between the first and second sides of the backing layer and that terminate at respective apertures in the backing layer first and second sides, and a thermoformable porous layer attached to said second side of said backing layer; and
said second composite comprises a sound absorbing and a sound blocking layer,
wherein said thermoformable porous layer of said first composite is in contacting relationship with said sound absorbing layer of said second composite.
2. The trim product of claim 1 wherein the fibrous primary layer comprises a matrix of thermoplastic fibers.
3. The trim product of claim 2 , wherein the matrix comprises a woven matrix of thermoplastic fibers.
4. The trim product of claim 2 , wherein the matrix comprises a non-woven matrix of thermoplastic fibers.
5. The trim product of claim 1 , wherein the secondary layer of thermoplastic material comprises one of a polyethylene, ethylene vinyl acetate (EVA), and blends thereof.
6. The trim product of claim 1 , wherein the sound absorbing layer comprises fibrous material selected from the group consisting of natural fibers, man-made fibers, and blends of natural fiber and man-made fibers.
7. The trim product of claim 1 , wherein the sound absorbing layer comprises a foam.
8. The trim product of claim 1 , further comprising an underlayment layer located against an area of the second composite.
9. The trim product of claim 1 , wherein the sound blocking layer comprises a filled polymer.
10. The trim product of claim 1 , wherein the sound blocking layer comprises a thermoplastic polymer.