Comparison of Bending Properties of Sandwich Structures Using Conventional and 3D-Printed Core with Flax Fiber Reinforcement

The growing interest in sustainable materials has shifted focus toward the use of natural fibers in composite structures as potential substitutes for synthetic fibers. In this study, the bending properties of conventional sandwich structures are compared with alternative designs that incorporate natural fibers and 3D-printed sandwich cores. The mechanical properties of sandwich structures composed of glass fiber with a traditional core and flax fiber with both conventional and 3D-printed cores were evaluated through 3-point bending tests (EN 310) and density profile analysis. Results indicate that the 3D-printed core structure achieved an average modulus of elasticity of 2271 MPa and a bending strength of 30.9 MPa, alongside a lower density profile than conventional materials. However, natural fibers may reduce the saturation quality of foam cores compared to glass fibers. These findings confirm that 3D-printed cores present a competitive alternative for applications requiring precisely engineered structures, with particular promise in sustainable material development.