Study of Transmission and Haze of Translucent Wood Based on Wood Density and Hyperspectral Analysis of Wood Fabrication

Abstract

Translucent wood is a biocomposite material fabricated by altering the chemical structure of the wood and impregnating the structural voids with a polymer that closely matches the refractive index of the structure of the wood. This work reports on the study of translucent wood fabricated using five different diffuse porous hardwood species and records the transmission and haze measurements of each of these species’ samples. This work highlights the trends between the measured transmission and haze on one hand and the anatomical differences and/or similarities of these species on the other hand. In terms of the anatomy of wood, we attempt to link the anatomical density of wood to the observed optical properties. The study first demonstrates the efficient removal of lignin and the proof of polymer impregnation in order to obtain translucent wood using hyperspectral imaging for spatial recognition of lignin and resin in the samples. Three methods of optical transmission measurement are presented here, as well as results on the wood densities obtained using two different methods: the first method calculates the structural ratio using image segmentation between the wood and the empty pores (lumen) and the second method uses the ratio of water-saturated and dry wood weight using the water immersion method. It is concluded that there are correlations between the density of the wood and the optical properties, particularly noting that the optical transmission of translucent wood decreases as the wood density increases. On the other hand, no clear correlations were observed between the structural properties and the haze properties of the material. Some potential explanations are given and open the way to further studies and understanding of wood structure using optical methods.