Mechanical Properties of the Polyester Hybrid Composite Reinforced by Fiberglass and Bamboo Blades as the Replacement Materials for 10GT Boat

Traditional hand-laid fiberglass reinforced plastic (FRP) 10 GT fishing boats often fall short of Indonesian Classification Bureau (BKI) standards, lacking the required tensile strength (98 MPa), modulus elasticity (6.86 GPa), and bending strength (150 MPa) with MOE 6.86 GPa. The extensive production of ships in Indonesia has led to increased demand for fiberglass, contributing to carbon emissions and air pollution, exacerbating global warming. This study explores the feasibility of environmentally friendly alternatives by partially replacing the fiberglass layer with a thin bamboo woven twill strip (5mm wide). Tensile and bending tests were conducted on composite specimens combining fiberglass and bamboo to assess compliance with BKI sailing standards. Tensile tests followed the American Standard Testing and Material (ASTM) D638, while bending tests adhered to ASTM D790 standards. Alkalized bamboo strips exhibited tensile strengths of 111.718 MPa (without alkalization) and 221.692 MPa (with alkalization). Hand lay-up FRP testing, with and without a press, indicated superior results for specimens with a press (tensile: 221.856 MPa, bending: 229.856 MPa) compared to those without (tensile: 112.227 MPa, bending: 228.476 MPa). Further experiments involved four-layer hybrid composites, replacing one fiberglass layer with woven bamboo in WR 800 and CSM 450 sections. The WR 800 replacement yielded tensile strengths of 106.316 MPa and 166.234 MPa, while the CSM 450 replacement resulted in strengths of 118.806 MPa and 62.451 MPa. The study successfully identified a hybrid composite composition, incorporating woven bamboo (WR800), that meets BKI standards for 10GT vessels in FRP composites with a press.