Vacuum Infusion as a Processing Route for Transparent Wood Laminates

ABSTRACT Transparent wood (TW) has attracted increasing attention as a bio‐based material for daylighting and building‐envelope applications due to its optical functionality, low thermal conductivity, and favorable strength‐to‐weight ratio. However, its practical implementation remains limited by challenges associated with polymer impregnation, interfacial cohesion, and thickness‐dependent performance degradation. In this study, the vacuum infusion process (VIP), a well‐established manufacturing technique in composite engineering, is systematically evaluated as a processing route for the fabrication of TW laminates from Pinus elliottii veneers and epoxy resin. Partial delignification achieved an ~88% reduction in lignin content, promoting effective resin infiltration into the wood cellular structure. Optical characterization revealed high transmittance in thin laminates, reaching up to 97% at 700 nm for single‐layer transparent wood (TW‐1). With increasing laminate thickness, transmittance decreased by ~22%, ~25%, and ~65% for TW‐2, TW‐3, and TW‐5, respectively, primarily due to increased optical path length and cumulative interfacial scattering. Thermal analysis indicated that epoxy impregnation partially compensated for the reduced thermal stability of delignified wood. Dynamic mechanical analysis demonstrated effective stress transfer and strong interfacial synergy in thin and intermediate laminates, while tensile testing showed that TW‐1 exhibited a 25% increase in strength compared to natural wood and a 258% increase relative to neat epoxy. Overall, the results demonstrate that vacuum infusion is a viable and scalable processing route for the fabrication of TW laminates for non‐structural building components, while also revealing critical thickness‐dependent limitations that must be addressed to enable reliable application in daylighting and architectural systems.