The rapid advancements in Additive Manufacturing (AM) technologies have revolutionized modern production methods, providing unparalleled opportunities for sustainable innovation in the process industry. This study focuses on the tensile investigation of multi-infill lattice structure components fabricated using Fused Deposition Modeling (FDM), an extrusion-based AM technique. Despite the wide adoption of FDM, achieving optimal mechanical properties for functional applications remains challenging. To address this, multi-infill patterns incorporating alternating Gyroid and Cubic stacking sequences were explored to enhance performance metrics such as strength-to-weight ratio and failure resistance.

Polylactic Acid Plus (PLA+), a biodegradable material with improved toughness and heat resistance over standard PLA, was employed to fabricate specimens at a constant 60% infill density. Tensile evaluation was conducted in accordance with ASTM standard.

The results revealed the diverse mechanical responses across both single and multi-infill patterns, with significant variations in tensile strength and ductility depending on the geometry and stacking sequence. Within multi-infill configurations, the Gyroid-Cubic-Gyroid (GCG) pattern demonstrated a favorable balance of stiffness and ductility, while other configurations exhibited unique strengths influenced by their specific stacking sequences. Multi-infill designs were found to introduce distinct stress distribution characteristics due to their layered transitions, which provided opportunities for tailoring mechanical properties for specific applications.

This study underscores the potential of multi-infill strategies to achieve customizable mechanical performance while offering insights into optimizing stacking sequences for tensile applications. The findings contribute to the development of sustainable additive manufacturing practices, with future research directed at improving interlayer bonding and exploring advanced hybrid geometries.

Index Terms- FDM, multi-infill patterns, tensile strength, PLA+, additive manufacturing