STUDI EKSPERIMENTAL VARIASI KETINGGIAN PENGASAPAN SERAT PINANG DAN SERAT SABUT KELAPA UNTUK MENINGKATKAN SIFAT MEKANIK KOMPOSIT HYBRID

Abstract

Hybrid composite materials were fabricated using areca nut fibers and coconut coir fibers arranged randomly, with a polyester resin matrix. The research variable was the variation in fiber smoking height, namely 70 cm, 100 cm, and 130 cm, with a smoking duration of 3 hours. Specimens were manufactured using the press mold technique. Impact testing referred to the ASTM D256-00 standard, tensile testing followed ASTM D638-02, and morphological analysis was conducted through fracture surface observations. The test results indicate that smoking height has a significant effect on the mechanical properties of the hybrid composites compared to untreated fibers. In the impact test, the highest absorbed energy and impact strength were obtained at a smoking height of 130 cm, reaching 2.7034 Joules and 0.0263 J/mm², respectively, while the lowest values were recorded at 70 cm, with 1.9114 Joules and 0.0173 J/mm². In tensile testing, the highest values were also achieved at 130 cm, with a tensile strength of 15.5015 N/mm² and a modulus of elasticity of 3659.8573 N/mm². The lowest tensile strength was found at 70 cm (13.0380 N/mm²), while the lowest modulus of elasticity was recorded at 100 cm (1221.0344 N/mm²). Macroscopic observations showed that fracture characteristics were dominated by fiber pull-out, debonding, overload, and crack deflection phenomena. These findings indicate that areca fibers and coconut coir fibers provide strong yet brittle material characteristics and demonstrate improved interfacial bonding at the optimal smoking height.