Determination of high-temperature and low-humidity treatment time for larch boxed-heart timber

The larch boxed-heart timbers with a cross section of 100 × 100 mm were dried after steamed at 100 °C dry-bulb temperature and 0 °C wet-bulb depression for 5 h, and then dried at 120 °C dry-bulb temperature and 30 °C wet-bulb depression for 8, 12 and 16 h, respectively, in order to determine optimal treatment time for the timber. This study indicated that the pretreatment of 12 and 16 h prevented both the surface and internal check of the timber. However, the pretreatment delayed drying time by at least 19%.