Flexural behavior of commingled jute/polypropylene nonwoven fabric reinforced sandwich composites

In this study, flexural behavior of nonwoven fabric reinforced sandwich composites from jute and polypropylene (PP) fibers was investigated. Jute/PP composite plates reinforced with jute/PP commingled nonwoven fabrics of different jute/PP fractions were used as facing materials in sandwich production. Balsa wood, polyester (PET) foam and PP honeycomb were used as core materials. Jute/PP nonwoven fabrics were treated with NaOH solution prior to sandwich production in an attempt to improve the fiber–matrix adhesion and the quality of facing-core bonding. The flexural behavior of the sandwiches was investigated experimentally as well as using Euler–Bernoulli and Timoshenko beam theories. The flexural properties of the sandwiches improved as the jute fiber content increases. Euler–Bernoulli model yielded smaller deflection values when compared to experimental results whereas Timoshenko model provided a good estimation of sandwich flexural properties. The effectiveness of fiber/matrix adhesion and facing/core bonding was determined by conducting scanning electron microscopy (SEM) analysis.