Experimental investigation of temperature-difference response in 3D-printed PLA structures filled with bio-based walnut shell/epoxy composites

This study intends to experimentally investigate the temperature-difference response in three-dimensional (3D)-printed polylactic acid (PLA) components filled with bio-based walnut shell/epoxy composites. A fixed 35 wt.% walnut shell particles are used with epoxy as a composite to fill the voids in the PLA-manufactured frames. The Taguchi L9 array modified the print angle (45°, 50°, and 55°), infill percentage (10%, 15%, and 20%), and number of walls (1, 2, and 3). Four thermocouples are used at fixed locations in the same laboratory enclosure, with a nominal electrical input of 100 W as the heating source. The response is specifically defined as the stable temperature difference (Δ T = T 2 − T 1 ), rather than thermal resistance or thermal conductivity. The mean and temporal standard deviation are calculated from the final five quasi-steady readings. Configuration L3 (45°, 20% infill, and three walls) produces the highest stable Δ T of 21.50 ± 0.14 K, which is 61.7% greater than that of the pure-PLA reference under identical test conditions. The larger-is-better Taguchi analysis ranked infill first (69% of the summed factor ranges), followed by print angle (20%) and number of walls (11%). As a result, this strategy may screen the temperature-difference response of samples containing agricultural waste fillers in additively manufactured hybrid polymer systems, depending on sample geometry. This in turn would offer a cost-effective, environmentally friendly, and efficient solution for cutting-edge thermal management in electronic insulation applications.