INVESTIGATION ON RELATION OF MATERIAL THICKNESS AND DENSITY AGAINST SOUND ABSORPTION BEHAVIOURS IN (SISAL/PALM) E-POXY HYBRID COMPOSITE

Abstract

This study investigates the physical, mechanical, thermal, and acoustic properties of sisal/palm fiber reinforced epoxy hybrid
composites fabricated with different weight ratios (Samples A, B, and C). The influence of thickness and density on sound absorption capacity
(SAC) is analyzed, along with the relationship between thermal conductivity and acoustic performance. Results show that an increase in thickness
and density significantly enhances sound absorption, with Sample C exhibiting the highest SAC due to improved fiber–matrix interaction and
porous structure. Thermal conductivity decreases with increasing sound absorption, indicating better insulation performance, particularly in
Samples B and C. Mechanical properties such as tensile, flexural, and impact strength are also found to be superior in Sample C, supported by
strong interfacial bonding observed in SEM analysis. Additionally, Sample C demonstrates lower moisture absorption and better structural
integrity. Overall, the study confirms that sisal/palm hybrid composites, especially Sample C, are highly suitable for applications requiring
combined thermal insulation and sound absorption performance.