Development of 3D Printed Biodegradable Poly-lactic Acid/Polyurethane Foams/Milled Glass Fibers of Sustainable Composites with Application on Helmet

Composite materials primarily contribute to engineering applications. The increase in additive manufacturing technology has many advantages in the manufacturing of composite materials. This study aims to design and fabricate a tri-material structure (TMS) composed of a 3D-printed poly-lactic acid (PLA) lattice frame infilled with polyurethane foams (PUFs) reinforced with milled glass fibers (MGFs). The mechanical behavior of the fabricated composite samples was investigated and compared to the PLA lattice of the mono-material (MMS) and PLA/PUFs of the bi-material structure (BMS). The MGFs content in TMS was varied at 1.25, 2.5, 3.75, and 5 vol