Thermo-hydro-mechanical densification of hemlock

The effect of Thermo-Hydro-Mechanical densification on selected properties of western hemlock was investigated. The drive was to explore the possibility of using hemlock as a replacement for expensive hardwoods for flooring applications. Kiln-dried boards at about 12% moisture content were subjected to densification in a hot press. As a special treatment, half of the samples were surface-sprayed with water before densification and three pressing times (5, 10, and 15 min), as well as temperature levels (120 degrees C, 160 degrees C, and 200 degrees C) were used. Sample density, hardness, colour change, and abrasion resistance were evaluated after densification. Data analysis revealed that the temperature level, densification time, and type of pre-treatment were statistically significant factors. Compared to controls, densification significantly improved density, hardness, and abrasion resistance by 197%, 386%, and 437%, respectively. As a possible desired aesthetic feature, this process darkened hemlock by about 200%.

Automated summary

The study found that temperature level, densification time, and type of pre-treatment were significant factors in Thermo-Hydro-Mechanical densification. Densification significantly improved the density, hardness, and abrasion resistance of western hemlock, while also darkening it by about 200% as a possible aesthetic feature.