Utilizing Waste Cotton/Pigeon Pea Stalk Fibers Composites for Enhanced Sound Absorption and Insulation in Automotive Interiors

Figures & data

Figure 1. A -Cotton fibre and B- Pigeon pea fibers.

Figure 2. Cotton/Pigeon pea composite materials.

Figure 3. Impedance tube setup methods.

Table 1. Properties of composite materials.

Sample	Thickness (mm)	Density (g/cm^3)	Porosity %	Airflow resistance (cm^3/s/cm^2)	Thermal Conductivity (W/mK)	Sound Absorption Coefficient % (SAC)
S1C	12.03	0.1323	0.769	34.8	0.137	0.15
S2P	12.85	0.1497	0.919	35.6	0.166	0.31
S3C/P	13.05	0.1366	0.924	37.6	0.128	0.18
S4C/P	12.78	0.1212	0.891	38.5	0.147	0.33
S5C/P	13.04	0.1244	0.884	36.5	0.127	0.232
S6C/P	13.02	0.1539	0.894	39.3	0.138	0.361

Figure 4. SEM images of composite (A) cotton fibers composites (B) Pigeon pea fibers composites.

Figure 5. Sound absorption performances of S1C, S2P, S3C/P, S4C/P, and S5C/P & S6C/P.

Figure 6. Influence of thickness on sound absorption.

Figure 7. Influence of density on sound absorption.

Figure 8. Influence of porosity on sound absorption.

Figure 9. Influence of airflow resistance on sound absorption.

Figure 10. Influence of thermal conductivity on sound absorption.