Mechanical and environmental performance of laminated composite plates reinforced with natural and synthetic fibers: a comparative study of flexural, water absorption and swelling characteristics
D. R. Rajkumar, A. Saravanan, Nikunj Rachchh, Ranitha Rajendran, Sekar Vijayakumar, Nagaraj Patil, Aditya Kashyap, A. Karthikeyan, Hari Prasadarao Pydi
Abstract
This study investigates the flexural properties, water absorption (WA) and swelling behaviour (ST) of multi-layered composites reinforced with natural fibers (Ramie and Jute) and synthetic fibers (E-glass and Basalt) using Unsaturated Isophthalic Resin (UIR) and epoxy resin as matrices. The primary objective is to assess the influence of fiber type, orientation and layer configuration on the mechanical properties and environmental sustainability of hybrid composites. Five composite plates with different fiber orientations were fabricated using the compression moulding method to minimize void content: Ramie/UIR (R plate), Jute/IR (J plate), Ramie/Jute/UIR (RJ plate), Basalt/Epoxy (B/E plate) and E-glass/Epoxy (G/E plate). The results showed that the R plate had the lowest flexural modulus, with B/E and G/E plates exhibiting superior bending resistance. The flexural strength of composites followed a similar trend, with the B/E plate performing 4.4% better than the G/E plate. Regarding water absorption and swelling behaviour, the J plate demonstrated the lowest water absorption, while the RJ plate showed higher swelling, attributed to differences in fiber weaving patterns and hydrophilic properties. The Basalt/Epoxy composites exhibited lower void content and superior performance in water absorption and swelling compared to E-glass/Epoxy composites. These findings highlight the role of fiber composition, weaving patterns and matrix materials in determining composite behaviour. This research offers valuable insights for designing high-performance materials for applications in industries like aerospace, automotive and marine, where resistance to transverse loading and moisture exposure was crucial.