Hybrid Kevlar– Agave sisalana fiber polymer laminates: a study on mechanical performance and microstructural analysis

Abstract Hybrid fiber-reinforced composites are increasingly being explored to replace traditional heavy armor materials in personal protective systems due to their potential for high strength-to-weight ratios and enhanced energy absorption. However, balancing performance, sustainability, and manufacturability remains a key challenge. To address this, we aimed to develop and evaluate a Kevlar–sisal hybrid laminate reinforced with epoxy resin, targeting improved mechanical performance for protective structural applications. Using hand lay-up fabrication followed by Abrasive Water Jet Machining, a five-layer laminate (Kevlar and sisal) was produced and tested. Tensile, flexural, impact, and interlaminar shear tests were conducted per ASTM standards, supplemented by SEM imaging for failure analysis. The composite exhibited consistent tensile strength (up to 98.14 MPa), good flexural capacity (up to 89.5 MPa), high energy absorption (up to 9.2 J), and strong interlaminar bonding (up to 12.08 MPa). SEM images revealed minimal fiber pull-out and robust matrix adhesion. These results suggest the laminate’s potential for use in protective vests and structural shielding. Future work will explore layering optimization and hybridization with ceramic or shear-thickening layers for improved ballistic resistance, as well as environmental aging tests for long-term performance validation.