• UHMWPE fiber reinforcement increases HDPE tensile strength by up to 45% and modulus by 60% at optimal 20 wt% fiber loading.
• Surface treatment of UHMWPE fibers significantly improves interfacial adhesion, leading to better load transfer and reduced fiber pull-out.
• SEM analysis confirms that strong interfacial bonding is critical for enhancing composite mechanical performance and failure resistance.
• The developed HDPE/UHMWPE composites exhibit excellent impact resistance, making them suitable for high-performance engineering applications.