The Effect of Galangal Fiber Mass Fraction on the Bending Strength of

Abstract

This study examines the effect of galangal fiber mass fractions on the bending strength of polyester resin composites. The objective is to determine how varying fiber content influences mechanical performance. A quantitative experimental design was employed, with composite specimens fabricated using the hand lay-up method and fiber mass fractions of 6%, 8%, and 10%. Samples were prepared according to ASTM D Type 4 standards, with three replicates per group to ensure reliability. Data were collected using digital scales, grinders, molds, and mechanical testing machines. Statistical analysis involved descriptive statistics and T-tests at a 0.05 significance level, complemented by correlation coefficient evaluation. Results showed that the composite with 10% fiber content achieved the highest average flexural strength of 40.55 MPa, while 8% fraction had the lowest at 31.76 MPa, and 6% fraction yielded 38.38 MPa. However, T-test analysis indicated no statistically significant effect of fiber mass fraction on bending strength (p = 0.771). The study concludes that within the tested range, galangal fiber content does not significantly improve the bending performance under current fabrication and testing conditions. Future research should explore wider fiber content ranges and alternative fabrication methods to optimize reinforcement potential