<![CDATA[Partition walls are widely used in modern building construction due to their cost-effectiveness, lightweight nature, and ease of installation. One innovation in partition material development involves utilizing natural fiber waste, such as coconut coir, as reinforcement for sandwich composites. This study aims to analyze the effect of coconut coir fiber length in the "skin" layer on the impact strength of sandwich composites intended for use as wall partition materials. A quantitative experimental method was employed, utilizing two fiber length variations—long fibers (uncut natural fibers) and short fibers (1–2 cm)—at a volume fraction of 40% fiber and 60% epoxy resin. Impact testing was conducted using an Izod impact testing machine in accordance with ASTM D256 standards. The results indicate that specimens with short fibers exhibited an average impact energy of 14.57 Joules and an average impact strength of 0.1175 J/mm², whereas specimens with long fibers showed an average impact energy of 14.17 Joules and an average impact strength of 0.1142 J/mm². Although the difference in impact strength between the two variations was relatively small (±0.0033 J/mm²), the short fibers demonstrated a more uniform distribution within the matrix, thereby inhibiting crack propagation more effectively than the long fibers. Thus, coconut coir fiber length influences the impact strength of sandwich composites, with the short fiber variation (1–2 cm) tending to yield slightly higher impact strength compared to the long fiber variation.]]>
