Comprehensive analysis of heat treatment effects on PLA-wood biocomposites

PurposeThis 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.Design/methodology/approachSamples 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.FindingsHeat treatment improved mechanical strength and moisture resistance of PLA-wood. The highest tensile strength was achieved at 100 degrees 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 degrees 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.Originality/valueThis 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.