Volume 2 - Issue 3, May - June 2026

This study investigates the processing-structureproperty relationships of polyurethane foam core sandwich composites reinforced with bamboo Z-pins, focusing on the influence of manufacturing techniques on their mechanical performance. The sandwich panels were fabricated using the hand lay-up and vacuum-assisted resin infusion (VARI) method, and their bending behavior were systematically evaluated. The insertion of bamboo Z pins aims to increase reinforcement through thickness and reduce delamination, a critical failure mode in sandwich structures. The results show that the manufacturing route significantly influences the quality of resin impregnation, interfacial bonding, and overall structural integrity. Composites produced via VARI show improved mechanical performance compared to those manufactured by the hand lay-up method, mainly due to reduced void content and increased fiber-matrix adhesion. The presence of bamboo Z pins contributes to improved load transfer and damage tolerance; however, its effectiveness is highly dependent on the quality of interfacial bonding and resin infiltration. The bending performance shows obvious improvement indicating the important role of Z-pin in suppressing delamination and improving coresurface interaction under bending load. Failure analysis further confirmed the transition from interfacial debonding in specimens fabricated by the hand lay-up method to a more cohesive and progressive failure mode in composites fabricated by the VARI method.

Agus Dwi Catur, I Dewa Ketut Okariawan,"Processing–Structure–Properties Relationship of Bamboo Z-Pinned Sandwich Composites: Comparison of Hand Lay-Up and VARI Techniques" International Journal of Advanced Multidisciplinary Research and Educational Development, V2(3): Page(938-944) May-June 2026. ISSN: 3107-6513. www.ijamred.com. Published by Scientific and Academic Research Publishing.