This study aims to investigate the effects of heat treatment on the mechanical and visual properties of PLA-wood samples. Three different heating temperatures and three different durations were applied to determine their impact on tensile strength, hardness, moisture resistance, dimensional stability, surface quality and visual appearance.
Samples were designed according to ASTM standards and produced via additive manufacturing. A full factorial experimental design was used. A total of 11 experimental groups were created: one untreated, one dried-only and nine heat-treated. Mechanical and physical evaluations included tensile testing, Shore D hardness, surface roughness, moisture absorption and visual color changes using a custom-built low-cost colorimeter developed specifically for this study.
Heat treatment improved mechanical strength and moisture resistance of PLA-wood. The highest tensile strength was achieved at 100 °C for 90 min, showing a 12.8% increase compared to the untreated group. Heat treatment increased hardness and brittleness while reducing elongation and moisture absorption. Dimensional changes stabilized after 100 °C for 90 min, and color generally darkened with increasing temperature. These findings indicate that heat treatment is effective for improving the performance and appearance of PLA-wood composites.
This is one of the most comprehensive heat treatment studies on PLA-wood in the literature, incorporating five distinct testing methods. A novel, low-cost colorimeter was developed for visual analysis. The results contribute significantly to the limited body of work on PLA-wood biocomposites and offer guidance for enhancing their functional and aesthetic properties through post-processing.
