Sound attenuating material for use within vehicles and methods of making same

摘要

Sound attenuating composite articles and methods of making same are provided. Sound attenuating composite article include first, second and/or third and/or fourth layers of material. The first layer of material may be either an acoustic fiber batting and/or an acoustic foam material and may be an elastic or inelastic material. The second layer of material is a thermoplastic material that is fused to a surface of the first layer of material. The third layer of material is a thermoplastic material that is fused to a surface of the second layer of material. The fourth layer of material is a woven or non-woven mixture of fibers, such as scrim material, that is attached to a surface of the third layer of material. Selected portions of the sound attenuating composite article are heated and then compressed (referred to as "tuned") so as to have an acoustic impedance that is greater than an acoustic impedance of adjacent portions.