Effect of thermo-hydro-mechanical densification on the wood properties of three short-rotation forest species in Costa Rica

Abstract

Alnus acuminata, Vochysia ferruginea, and Vochysia guatemalensis are three low-density wood species used for reforestation in Costa Rica. The goal of this work was to study a thermo-hydro-mechanical densification process and test the characteristics of densified wood of these species. Twelve densifying treatments based on temperature, compression time, and use/no use of steam were tested. The variables of the densification process and the properties of the densified wood were determined. The results showed that the densification percentage was over 80% for wood of A. acuminata and over 70% for wood of V. ferruginea and V. guatemalensis. In the three species, the densification process was influenced by initial density. The influence of temperature during the densification process affected the heating rate and color change. An increase in the modulus of elasticity and modulus of rupture in static bending and in the hardness of the densified wood relative to the normal wood was observed, as well as a clear positive correlation of the properties with final density and maximum load, the latter being highly correlated with initial density. This showed that initial density was significant in the densification process and affects wood properties.

Research Progress of Wood Cell Wall Modification and Functional Improvement: A Review

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Modification of Poplar Wood via Polyethylene Glycol Impregnation Coupled with Compression

“…Phase-changeable energy storage materials are highly susceptible to loss during heat exchange, and renewable wood may be an ideal carrier for effective loss suppression due to its high porosity and high pore density [18]. Polyethylene glycol (PEG) impregnation is a highly effective strategy for wood modification.…”