Effect of infrared preheating on the adhesion of PLA 3D directly printed onto beech and spruce woodKariž, Mirko (Avtor) Krapež, Daša (Avtor) Lovrečič, Matija (Avtor) Šernek, Milan (Avtor) Straže, Aleš (Avtor) direct 3D printingwoodIR heatingadhesionbond shear strengthThis study investigated the effect of infrared (IR) preheating on the bond shear strength of polylactic acid (PLA) directly printed onto beech and spruce. Wood surfaces were exposed to IR radiation for 60, 90, or 120 s before printing and compared with unheated controls. Surface-temperature histories were recorded, individual heating segments were fitted using square-root-of-time model, and bond performance was assessed through shear testing and fracture-surface examination.20262026-09-29 08:20:47Neznano188812sl