Effect of Stacking Sequences, Fabric Orientations, and Chemical Treatment on the Mechanical Properties of Hybrid Woven Jute–Ramie Composites

Natural fibres have been widely used in advanced applications, especially in the automotive industry. These fibres are inexpensive, non-abrasive, environmentally friendly, biodegradable, and possess low density with good mechanical properties. The main issue in using natural fibres is their incompatibility with a polymer matrix that lowers the mechanical properties. Therefore, this research analyses the effect of stacking sequences, fibre orientations, and alkali treatment on the mechanical properties of hybrid jute (J) and ramie (R) reinforced vinyl ester (VE) composites. Initially, woven fibres were fabricated based on the 3 and 4—layer stacking sequence with 0° orientation. The characterisation was done to analyse its properties. It was found that the RJJR stacking sequence possessed a tensile strength higher value of 28.90 MPa. The results for the RJJR sequence were fabricated with various fibre orientations such as 0°, 30°, 45°, and 90° to understand the effect of fibre orientation towards the tensile and flexural properties. The tensile and flexural strength with 0° fibre orientation is significantly higher than the other orientations with values of 28.90 MPa and 66.81 MPa, respectively. Besides, alkali treatment with 5 wt.% and 10 wt.% was used to enhance the mechanical properties, where 0° RJJR with 5 wt.% indicated maximum flexural strength with 34.50% increment compared to untreated RJJR. In conclusion, the combination of fibre orientation and lower alkali treatment concentration (5 wt.%) is highly beneficial in improving fibre hybrid composites' mechanical properties.