Optimization of adhesion properties of PLA on cork substrate via FDM: A Taguchi experiment design

This study investigates the optimization of interfacial adhesion between polylactic acid (PLA) and cork substrates using fused deposition modeling (FDM), a topic scarcely explored in the literature. The research question seeks to identify FDM parameters that most strongly influence adhesion strength and microstructural porosity in PLA–cork laminated structures. Cork, a lightweight, elastic, and sustainable material, was selected as a novel substrate for functional, laminated structures. A Taguchi L36 fractional factorial design was employed to systematically evaluate six process parameters—build orientation, infill density, layer height, printing speed, contour lines, and bed temperature—and their effects on adhesion and porosity. Mechanical shear tests revealed a maximum adhesion strength of 1.39 N/mm under optimal conditions. Taguchi analysis indicated build orientation and infill density to be the most influential factors (delta = 0.2591 and 0.2484, respectively). Microstructural analysis showed that increasing infill density and adding contour lines reduced total porosity from ∼25 % to ∼13 %, enhancing interfacial bonding. Regression and signal-to-noise analyses quantifying the synergistic effects of key parameters, providing a predictive framework for optimizing adhesion. The findings demonstrate the value of integrating FDM technology with natural cork to produce sustainable, high-performance laminated structures. This approach addresses the need for better materials in applications that demand excellent layer adhesion, which is the main study’s central contribution.