Evaluation of Physico-mechanical Properties and Durability of Larix kaempferi Wood Heat-treated by Superheated Steam

Abstract

In this study, green Larix kaempferi lumber was heat-treated by using superheated steam (SHS) at a pilot scale and then various physico-mechanical properties of the heat-treated wood were evaluated and compared with the properties of conventional hot air (HA) heat-treated wood. Decay resistance of brown rot fungi and compressive strength parallel

Changes of major chemical components in larch wood through combined treatment of drying and heat treatment using superheated steam

“…At the beginning of the combined treatment, the temperature and pressure of the SHS and temperature of the lumber increased rapidly. When the temperature and pressure of the SHS reached the target temperature (250°C) and the target pressure (0.5 MPa), the temperature of the lumber reached the saturation temperature (151.8°C) of steam at 0.5 MPa and was maintained for 3 h. Park et al [19] reported that the wood specimen was oven-dried when the temperature of the wood specimen was maintained constantly and re-increased. In other words, the water in the wood was completely removed for the duration of the constant temperature, and the temperature of the wood was re-increased by the heat energy which had been used to remove the water in the wood was used to heat the wood.…”

Evaluation of Deterioration of Larix kaempferi Wood Heat-treated by Superheated Steam through Field Decay Test for 12 Months

“…Heated at a high temperature (160~260℃), the principal components that consist of the cell walls of wood (cellulose, hemicellulose, and lignin, etc.) experience chemical changes like thermal hydrolysis process, which results in changing the physical-dynamic as well as weatherproof performance (Militz, 2002;Park et al, 2016). Various research on wood heat treatment as an environmental-friendly preservative and insect-proof process since the early 2000s has been conducted mainly in Europe.…”

“…Recently, there has been research on the heat treatment with superheated steam on wood (Park et al, 2012;Park et al, 2014;Park et al, 2016;Han et al, 2017;Park et al, 2017a;2017b). Superheated steam is a steam of which temperature is over the boiling temperature and is used to dry not only wood, but food or sewage sludge (Kim et al, 2008).…”

“…The heat treatment with superheated steam on wood offers low energy loss and high energy efficiency as the drying and heat treatment of wood are performed at the same time through a single process (Park et al, 2017a). The heat treatment on wood with superheated steam offers superior heat treatment effects to the existing hot air treatment process under the same temperature and duration as the former promotes the thermal hydrolysis process by steam at high temperature and high pressure (Park et al, 2014;Park et al, 2016). This means that the heat treatment with superheated steam causes considerable property changes to wood, such as the increase in the dimensional stability and bending and compressive strengths due to the increase in hydrophobic properties (Park et al, 2016).…”

“…The heat treatment on wood with superheated steam offers superior heat treatment effects to the existing hot air treatment process under the same temperature and duration as the former promotes the thermal hydrolysis process by steam at high temperature and high pressure (Park et al, 2014;Park et al, 2016). This means that the heat treatment with superheated steam causes considerable property changes to wood, such as the increase in the dimensional stability and bending and compressive strengths due to the increase in hydrophobic properties (Park et al, 2016). Furthermore, it has been reported that the decay lab test on heat-treated wood with superheated steam showed that its resistance to brown and white rot fungi greatly increased (Park et al, 2014;Korea Forest Service, 2016).…”