Abstract :
nnovation in the field of composite materials requires the creation of
materials that have optimum impact strength. One of them is by utilizing natural
fiber as an alternative to glass fiber replacement. Natural fiber composite
materials have almost the same impact strength as synthetic fiber composites. The
advantage of natural fibers is that they have high cellulose content which is
suitable when it is bounded by polymers.
The purpose of this study is to find out effects of time alkali immersion
on impact strength in ramie fiber composites. The material used is ramie fiber
with Yukalac 157 BQTN-EN polyester resin matrix. The method used in the
manufacturing process is hand lay-up. Composites consist of discontinous 15%
composite fiber volume fraction and 5% alkali (NaOH) immersion with 0, 1, 2, 3,
and 4 hours immersion variations. The tests were carried out using impact tests
with the specimens of ASTM D 256-03 standard.
The results of the composite impact test showed the impact value on the
variation of alkali immersion 0 (without immersion), 1, 2, 3, and 4 hours obtained
results of 0.090 J/mm², 0.082 J/mm², 0.072 J/mm², 0.068 J/mm², 0.066 J/mm². The
highest impact test occurred at variation without alkali immersion with 0.090
J/mm² and the lowest was at the 4 hours variation with 0.066 J/mm². From the
impact test it can be seen that soaking the ramie fiber with an alkali solution has
an effect on the impact strength. The longer the soaking time will damage the
fiber and decrease the value of impact strength