The Combined Effects of Linseed Oil and Heat Treatment on the Properties of Cypress and Maple Wood Part 1: Water Absorption, Mechanical Properties, and Sound Absorption Capacity

Abstract

The physical and mechanical properties of thermally modified wood impregnated with linseed oil were investigated to find the relationship between the treatment and the acoustic properties. The samples were impregnated with linseed oil (LO). Heat treatment was performed in an oven at four different temperatures, namely 160, 180, 210, and 240 °C. Statistically, the physical, mechanical, and acoustic properties of the treated wood were significantly intensified as compared to the control samples. The physical properties (water absorption) of the treated wood decreased by 72% as compared to the control group. However, while the increase in both MOR and MOE at 240 °C was 13%, the increase in CS at 240 °C was 7%. As a result of the heat treatment, the porosity increased by 33% as compared to the control group. At 240 °C the maximum SAC value was observed to be 0.71 at 5000 Hz and at 4500 Hz 0.78 and 0.80, respectively. The highest STL value, which was 69.9 dB, was observed at 1540 Hz and 3600 Hz. As a result of improved heat transfer, impregnating samples with LO before thermal modifications was observed to increase the efficiency of thermal modification.