Acoustic evaluation of Struto nonwovens and their relationship with thermal properties.

This paper presents an experimental investigation on the sound absorption behavior and thermal properties of Struto nonwovens by establishing relationship between these properties. Seven Struto nonwoven fabrics were selected to examine the noise reduction coefficient (NRC) and average values of sound absorption coefficients (<named-content>α¯</named-content>) as well as thermal properties, including thermal conductivity and thermal resistance. The Brüel and Kjær impedance tube instrument and Alambeta were used for the evaluation of acoustic and thermal properties, respectively. The influence of structural parameters on acoustic and thermal properties of Struto nonwovens were investigated and analyzed. The results showed that Struto nonwovens with higher thickness, finer fibers and higher fabric grams per square meter can provide better sound absorption performance. The effect of specific airflow resistance on sound absorption performance was also investigated. It is observed that sound absorption performance has a strong correlation with specific airflow resistance. The effect of porosity on specific airflow resistance and thermal properties was studied in detail. The result indicated that porosity has a strong correlation with specific airflow resistance and thermal properties. It was also observed that sound absorption, the NRC and <named-content>α¯</named-content> have an insignificant correlation with thermal conductivity, while they are strongly correlated with thermal resistance. The correlation coefficient of the NRC with thermal resistance is 0.9835, indicating that the NRC is directly proportional to the thermal resistance of Struto nonwovens. [ABSTRACT FROM AUTHOR]