Abstract :
Utilization composite materials is currently growing. It is increasingly in demand and
covers several fields such as aviation, housing, the public transportation industry, shipping,
and automotive. Composite materials have advantages, namely low density, lighter weight,
stronger, wear-resistant, corrosion-resistant, and economical.
This study aims to compare the hand lay-up method with the vacuum bag method as a
refinement of the hand lay-up method. In the vacuum bag method, the suction process was
carried out using a pump vacuum bag which aims to remove excess resin and air trapped in
the laminate so that composites with material properties were better than the combined results
of the hand lay-up method. The vacuum bag method was lighter than the hand lay-up method.
The material used was hemp fiber with a Yukalac 157 BQTN-EX polyester resin matrix and a
MEXPO catalyst. The composites were arranged randomly with fiber volume fractions of 10%,
12%, 14%, and 16%. The 5% alkaline treatment was carried out for 3 hours. The tensile testing
was carried out on 12 specimens with the dimensions referring to the ASTM D-638 standard.
The pull-test results of the tensile test on the specimens from both methods showed that
the specimens from the vacuum bag method had better material properties with a tensile
strength of 16% variation of 41.24 MPa. Meanwhile, the hand lay-up method with 16%
variation had the lower value as 22.42 MPa. Meanwhile, the results of the SEM (Scanning
Electron Microscope) analysis showed brittle fracture. Testing materials as interior (handle)
of the car by the standard SAE (Society of Automotive Engineering) standard is SAE J 1717
with a tensile test of 20-40 MPa. The 16% variation is recommended as a composite material
for the interior (handle) of a car because it has a strength value of 38.27 MPa.