Technological and chemical properties of heat-treated Anatolian black pine wood

Abstract

In this study the effect of heat treatment on air-dry density (D(m)), oven-dry density (D(0)), shrinkage (beta), swelling (alpha), fiber saturation point (FSP), compression strength parallel to grain (sigma(c//)), bending strength (sigma(b)), modulus of elasticity (MOE) in bending, Brinell-hardness (H(B)), equilibrium moisture content (EMC), chemical content and cellulose crystallinity of Anatolian black pine [Pinus nigra J.F. Arnold subsp. nigra var. caramenica (Loudon) Rehder] was evaluated. Specimens were subjected to heat under atmospheric pressure at 3 different temperature (130, 180 and 230 degrees C) and 2 different time levels (2 and 8 h). The value of D(m), D(0), beta, alpha, FSP, EMC, sigma(c//), sigma(b), MOE, holocellulose, 1% NaOH and alcohol solubility decreased, whereas, lignin content increased depending on the heating temperature and the time. Cellulose crystallinity of the specimens was not changed significantly. 130 degrees C showed minimum effect, on the other hand, 230 degrees C showed maximum effect on all properties of treated wood. Accordingly, for heat treatment process, 130 degrees C for 2 h should be applied in place where mechanical properties are important. However, 230 degrees C for 2 h should be used in place where a physical property is preferred. Consequently, heat treated Anatolian black pine woods could be utilized in applications for several purposes such as kitchen furniture, outdoor furniture and windows frames.