Analysis of the Influence of Thickness and Density on Acoustic Absorption of Materials Made from Used Cigarette Butts

Abstract

The effects of the density and thickness of samples made from used cigarette butts on acoustic characteristics were analyzed in this study. All the analyzed samples showed high acoustic performance, indicating that the fabrication of acoustic absorbing material may be a good use for this problematic waste (due to its toxicity, continuous generation, lack of recycling method, etc.). An increase in either density or thickness shifted the absorption characteristics of the samples to lower frequencies and increased the overall absorption. The relationships of the frequency and value of the maximum absorption coefficient with thickness and/or density were analyzed. The shift of the maximum absorption coefficient value due to varying thickness is in good agreement with previous studies.

Sound Absorption Performance and Mechanical Properties of the 3D-Printed Bio-Degradable Panels

“…The increase in the absorption coefficient for the three types of samples, compared to the results obtained for the double panels, was as follows: 39% for the single 40% triangular-PLA-coconut samples; 20% for the single 100% corrugated PLAbirch samples and 33% for the single 80% triangular-PLA samples. Therefore, it can be stated that sample thickness is very important in acoustic tests, as previously found in other studies [40,54,63].…”

Investigation into the Acoustic Properties of Polylactic Acid Sound-Absorbing Panels Manufactured by 3D Printing Technology: The Influence of Nozzle Diameters and Internal Configurations

“…The best absorption coefficient values (α = 0.91) were obtained for the Z 1 configuration, for a tilt angle of 31 • and for a sample thickness of 4 mm. An important factor that has a strong influence on the sound absorption coefficient is the sample thickness [48,60,61], and this was also validated in this paper, where the best results, for all the types of material studied, were obtained at a sample thickness of 4 mm.…”

A comprehensive review on triple R eco-management strategies to reduce, reuse and recycle of hazardous cigarette butts

“…According to experimental findings firstly, density increases will increase the overall absorption, however absorption maxima will drop. In short fluctuation in the density of CBs can diminish the absorption maxima but did not impose alteration in overall absorption [ 45 ]. Secondly, an increment in the thickness of CBs enforces absorption maxima at a lower frequency.…”

“…Frequency around 500–5000 Hz octave bands concludes that enhancement in density from 110 to 160 kg m −3 alters absorption spectra positively. Among all the frequencies, the maxima of absorption coefficient (0.8) were obtained at 2000 Hz [ 45 ]. The performance index of CBs as noise absorbent is high among other absorbents but presents few drawbacks.…”