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.