Abstract :
Natural Composite (NACO) is a material that could be developed in Indonesia.
Mechanically bonded composites reinforced by natural fibers can be improved by chemical
treatments such as the alkaline treatment. It is often used as it is more economical. The
purpose of this study was to study the effect of alkaline immersion on the bending properties
and impact of hemp fiber reinforced composites.
The main ingredient of the research is hemp fiber and transparent polyester resin
108. The hardener used is a MEKPO hardener with a concentration of 1%. The composite is
handmade. The composite consists of random hemp fibers, the volume fraction of composite
fibers is 15%, the alkaline quenching solution (NaOH) 5% with time variations of 0, 1, 2, 3, 4
hours. The flexural test specimen refers to ASTM D 790-03 and the impact test to ASTM D
256-03. The fracture section is examined to identify the fracture mechanism.
The results showed that the greatest flexural strength was obtained with immersion of
3 hours equal to 64,094 MPa. The highest impact resistance was obtained in fibers without
alkaline immersion of 0.013 J / mm². The stages of the composite failure were tensile failure
on the lower side, compression failure on the upper side, and the fiber failure on the pull out.