Comparison between the mechanical properties and environmental impacts of 3D printed synthetic and bio-based composites

The present work aims at studying both the mechanical properties and environmental impacts of two 3D printable composites materials: glass fiber reinforced polyamide (GlassPA) and bio-based hemp fiber reinforced polylactide (HempPLA). Hence, this study aims to provide a comprehensive overview of the two considered materials, supporting the sustainable development of industrial additive manufacturing processes. To this purpose, tensile specimens were produced using a Fused Deposition Modeling process and then tensile tested to evaluate the mechanical properties of the printed materials. The environmental impacts of both GlassPA and HempPLA were investigated using the Life Cycle Assessment methodology; a cradle to gate approach was chosen to evaluate all the relevant input of the tensile specimens production. Mechanical tests showed that synthetic composite is characterized by higher strength and stiffness values than the bio-based composite. However, HempPLA results in noticeably lower environmental impacts than GlassPA in terms of Cumulative Energy Demand and Global Warming Potential indicators, proving to be a feasible alternative to glass fiber reinforced polymers in application with low load conditions.