<![CDATA[Sandwich composites with a bamboo honeycomb core and coconut coir fibre face plates offer an alternative for lightweight structures that must absorb impact energy. This study examines the effect of coir fibre volume fraction in the face plate on the impact energy and impact strength of the composite. Fibres were alkali-treated in sodium hydroxide for one hour, then moulded with epoxy resin into 2 mm face plates at volume fractions of 30%, 40% and 50%. The core was assembled from bamboo strips into hexagonal cells of 10 mm cell side, 20 mm wall height and 1 mm wall thickness. Testing followed the Izod method of ASTM D256 with three specimens per fraction, and impact strength was taken as absorbed energy divided by the 136 mm² cross-section. Mean impact energy reached 6.93 J at 30%, 9.67 J at 40% and 7.50 J at 50%, equivalent to impact strengths of 0.0510, 0.0711 and 0.0551 J/mm². Scatter was wide, with standard deviations of 2.52, 5.80 and 3.32 J, and one-way analysis of variance gave F(2,6) = 0.37 (p = 0.71). The 40% composition is therefore best read as a working indication that needs confirmation with more specimens and tighter process control.]]>
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