Analysis of the Variation in Immersion Time on the Toughness and Macrostructure of Sansevieria Fiber Composites Using the Taguchi Method

Sansevieria fibers have potential as composite reinforcing materials due to their superior mechanical characteristics, but special treatment is required to improve their compatibility with polymer matrices. In this study, Sansevieria fibers were soaked in a solution of sodium chloride (NaCl) with time variations of 5, 7, and 9 days, then dried and processed into composites with resin epoxy matrix and hardener using the continuous lay-up method. Tests were carried out on the toughness of composites using the Charpy impact test method according to the ASTM E23-56T standard, while macrostructure analysis was carried out with an optical microscope. The results of the experiment were analyzed using the Taguchi method, with a Signal-to-Noise Ratio (S/N Ratio) approach to determine the optimal level of immersion time that results in the best toughness. In addition, an Analysis of Variance (ANOVA) was conducted to evaluate the significance of the effect of immersion time on the mechanical properties of composites. The results showed that increased immersion time contributed to increased composite toughness. The 9-day immersion time yielded the highest toughness value of 0.0074 J/mm², compared to 5-day (0.0036 J/mm²) and 7-day (0.0046 J/mm²) immersions. Analysis of the macro structure showed that longer immersion improves the bond between the fiber and the matrix, reduces the phenomenon of fiber pull-out, as well as improves load transfer in composites. Based on the results of Taguchi's analysis, the soaking time has a significant influence on the increase in toughness, with the optimal time obtained at 9 days of immersion in NaCl solution. Thus, this study confirms that the soaking treatment of Sansevieria fibers in NaCl solution can improve the toughness and macrostructure quality of natural fiber-based composites. These results can be a reference in the development of natural fiber-based composite materials for structural applications that require lightweight materials with high mechanical resistance. Keywords—, Sansevieria Fiber, NaCl Solution, Toughness, Microstructure, Taguchi Method