Enhancing Fatigue Resistance of Polylactic Acid through Natural Reinforcement in Material Extrusion

Area of Science:

• Additive Manufacturing
• Materials Science
• Polymer Engineering

Background:

• Polylactic acid (PLA) is a widely used biodegradable polymer in additive manufacturing.
• PLA often suffers from poor fatigue resistance and dimensional instability, limiting its applications.
• Natural fiber reinforcement offers a sustainable route to enhance PLA properties.

Purpose of the Study:

• To enhance the fatigue resistance of PLA in Material Extrusion (ME) using natural reinforcements.
• To investigate the effect of cellulose, coffee, and flax fibers on PLA's rotational bending fatigue behavior.
• To optimize printing parameters for improved dimensional accuracy and fatigue performance.

Main Methods:

• Incorporation of natural fibers (cellulose, coffee, flax) into PLA.
• Material Extrusion (ME) 3D printing of reinforced PLA components.
• Rotational bending fatigue testing and dimensional stability analysis.

Main Results:

• Cellulose reinforcement showed superior resistance to warping and shrinkage, leading to better dimensional accuracy.
• All tested natural fibers (cellulose, coffee, flax) significantly improved PLA's fatigue resistance.
• PLA reinforced with cellulose achieved 13.7 MPa stress at 70,000 cycles, outperforming unreinforced PLA.

Conclusions:

• Natural fiber reinforcement is an effective strategy to enhance the fatigue resistance and dimensional stability of ME-printed PLA.
• Cellulose is the most promising reinforcement for PLA in ME applications requiring high fatigue performance and dimensional precision.
• This research advances sustainable additive manufacturing by providing a viable method to improve PLA's mechanical properties.