LONGEVITY OF ADDITIVE MANUFACTURING THERMOPLASTIC COMPOSITE MATERIALS IN INFRASTRUCTURE APPLICATIONS
Published: 2024
Publication Name: ECCM21
Abstract:
The research focuses on evaluating the longevity of large-format 3D printed polymer composite parts for infrastructure applications, particularly concerning the effects of water immersion and freeze-thaw cycling. Two synthetic polymer composite materials – Carbon fiber reinforced acrylonitrile butadiene styrene (CF-ABS) and glass fiber reinforced polyethylene terephthalate glycol (GF-PETG), and one biobased polymer composite material – Wood fiber reinforced amorphous polylactic acid (WF-aPLA) were selected for this study. The 3D-printed specimens were subjected to accelerated ageing conditions following ASTM standards. Baseline mechanical properties were evaluated by tension testing a set of unaged specimens. The change in mechanical properties after 30, 60, and 90 days of accelerated water immersion and after 3, 6, and 9 freeze-thaw cycling were evaluated. The material properties were evaluated in two directions -along the direction of material deposition and across the layers. Results show significant reductions in mechanical properties, especially in bio-based materials, after 90 days of moisture exposure. Properties across layers were more affected than in the deposition direction. Biobased polymers saw the most decline, up to 45% in tensile strength and 40% in tensile modulus. Minimal changes occurred after 3, 6, and 9 cycles of freeze-thaw exposure.