Abstract:
This study developed and evaluated a sustainable hybrid composite based on bark cloth and glass fibers for lightweight automo-
tive and semi-structural applications. Hybrid laminates were fabricated via the hand layup technique with varying fiber weight
fractions (15–25 wt%), bark cloth-to-glass fiber ratios, and stacking sequences. Mechanical, physical, and microstructural charac-
terizations were performed to assess the effects of hybridization and laminate architecture on composite performance. The results
demonstrate that hybridization markedly improves the mechanical performance of bark cloth composites. Optimal properties were
achieved at a bark cloth-to-glass fiber ratio of 1:3 and a fiber weight fraction of 20 wt%, yielding tensile strength of 43.24 MPa, flex-
ural strength of 140.94 MPa, and impact strength of 78.6 kJ/m2 . Laminates with glass fibers positioned in the outer layers exhibited
superior flexural and impact resistance due to enhanced surface load-bearing capacity and stress transfer efficiency. Conversely,
excessive fiber loading (25 wt%) led to property degradation, attributed to insufficient resin wetting and fiber agglomeration. SEM
analysis confirmed that reduced voids and improved interfacial bonding in optimized hybrids governed the observed mechanical
enhancements. This work presents the first systematic investigation of bark cloth–glass fiber hybrid composites and demonstrates
that an optimized hybrid architecture can achieve a favorable balance between mechanical performance and sustainability. These
findings highlight the potential of bark cloth–glass fiber hybrids as promising candidates for lightweight automotive interior
components and semi-structural applications, contributing to the development of greener composite materials.
