Characterization of PLA/LW-PLA Composite Materials Manufactured by Dual-Nozzle FDM 3D-Printing Processes

Area of Science:

• Materials Science and Engineering
• Additive Manufacturing
• Polymer Composites

Background:

• Dual-nozzle fused-deposition modeling (FDM) 3D printing enables the creation of complex composite structures.
• Polylactic acid (PLA) and lightweight-polylactic acid (LW-PLA) offer distinct properties for customized material development.
• Controlling printing parameters is crucial for tailoring the mechanical performance of 3D-printed parts.

Purpose of the Study:

• To investigate the influence of nozzle temperature and infill density on the properties of PLA/LW-PLA composite structures.
• To analyze the effects of different layer arrangements (ST4, ST8, CH4) on printing behavior and mechanical response.
• To determine optimal printing conditions for balancing strength, toughness, and density in FDM-printed composites.

Main Methods:

• Three distinct composite cube structures (ST4, ST8, CH4) were designed and fabricated using dual-nozzle FDM.
• Printing time, weight, morphology, and compressive properties were systematically evaluated.
• Experiments were conducted across a range of nozzle temperatures (230°C, 240°C) and infill densities (up to 100%).

Main Results:

• Higher nozzle temperatures (230°C, 240°C) induced significant foaming in ST4 and ST8 structures at 100% infill.
• Foaming led to increased part dimensions (up to 103.5%) and reduced weight (up to 9.25%).
• The ST4-Com-PLA/LW-PLA-240 composite exhibited a 246.5% increase in toughness at 100% infill due to enhanced pore compression.

Conclusions:

• LW-PLA's foaming characteristics are amplified with continuous printing, most notably in ST4 structures.
• Nozzle temperature and infill density are critical parameters for controlling foaming, density, and mechanical properties.
• Optimal printing conditions of 230°C and 50% infill density provide a favorable balance of strength and toughness for diverse applications.