Sound absorption of gradient structure fabrics based on functional finishing with metal compounds

The common porous sound absorbing materials are thick and have a narrow sound absorption band. In order to design light and thin gradient structure functional fibrous assemblies with excellent performance of sound absorption and noise reduction, metal compounds with a heavy vibration damping characteristic were applied to a nonwoven by padding finishing, dipping finishing (DF) and spraying finishing. The influences of metal compound type, finishing method, the application amount of finishing agent and distribution of the finishing agent on nonwoven fabric for the sound absorption performance were studied. The results showed that the samples following DF had the largest amount of metal compound applied, and this processing method was beneficial to the construction of the gradient structure. The heavy vibration damping property of the metal compound could combine with the porous sound absorption mechanism of the nonwoven fabric to improve the sound absorption performance of fabric. The greater the amount of metal compound in the application, the better the sound absorption performance, and the effects of ferric oxide (Fe2O3) and barium sulfate (BaSO4) were particularly remarkable. Different finishing methods would affect the distribution of the metal compound on the material, which in turn affected the sound absorption performance.