Prediction of sound absorption performance of fibers coming from cigarette butts using a phenomenological model

This work deals with experimental and theoretical research about cellulose acetate fibers coming from cigarette butts. This waste, considered one of the most hazardous, numerous, and polluting waste all over the world, represents a high environmental risk. The possibility of using these fibers in sound-absorbing panels is evaluated. The acoustical properties are measured according to ISO 10534-2, and predicted using a phenomenological model over the frequency range from 100 Hz to 6400 Hz. This work includes the study of important non-acoustical properties for a better understanding of the porous structure. The Johnson-Champoux-Allard model provides good accuracy. The experimental results of the sound absorption spectrums show mean errors ranging from 1.1% to 9.0%. Moreover, it is possible to obtain non-acoustic properties of cellulose acetate fibers, which are difficult to obtain experimentally, using the Johnson-Champoux-Allard model and an inverse technique. The input parameters of this model are successfully obtained with low errors concerning the measurements (0.6–5.2% for porosity or 2.6–10.5% for flow resistivity). The results of the sound absorption spectrum at normal incidence of the cellulose acetate show very accurate predictions. The experimental results show values of sound-absorption coefficients close to 1.0 and sound absorption average ranging from 0.42 to 0.8. Therefore, these waste fibers are an alternative to the traditional porous absorbers, mainly composed of synthetic fibers or foams and petroleum-based resins.