Production of Injection Moulded Natural Fiber Reinforced Hybrid Composites and Assessment of Hybridization’s Effect on Mechanical Properties

Over the past two decades, rising environmental awareness, public concern over waste, and stricter government regulations have encouraged companies to reduce their reliance on petroleum-based fuels and products. Consequently, there is a clear need to find sustainable, eco-friendly substitutes for the materials currently in use. This shift has renewed attention on renewable resources and sparked wider interest in advanced composites and green materials research. With this in mind, the present work develops a hybrid composite reinforced with three different natural fibers in a single matrix and studies its mechanical behavior. The injection moulding process parameters were optimized using the Taguchi technique, and ANOVA was applied to identify the parameter with the strongest influence on the desired performance. This study investigated how varying quantities of three natural fibers influence the flexural strength, flexural modulus, and impact strength of hybrid composites. The findings show that injection moulding is an effective route for producing hybrid composites by reinforcing HDPE with three different natural fibers. The flexural strength and modulus of the hybrid composite improved with fiber reinforcement, whereas the impact strength of all fabricated hybrid composites was found to be lower than that of neat HDPE (13.5 J/m), with a more pronounced reduction observed at higher fiber loading (18 wt.%). Statistical analysis indicated that fiber loading (Wt.%) was the parameter with the greatest effect on the mechanical properties of these composites.