Effect of High-Temperature Treatment on the Mechanical Properties of Rowan (Sorbus aucuparia L.) Wood

Abstract

Heat treatment is a wood modification method that has been used to some extent in improving timber quality. The high temperature thermal treatment of wood is an environmentally friendly method for wood preservation. This technique has attracted considerable attention both in Europe and in North America in recent years.

This article presents the results of experimental studies on influence of heat treatment on the mechanical properties of Rowan (Sorbus aucuparia L.) wood performed in order to understand its role in wood processing. Samples were exposed to temperature levels of 120, 150, and 180°C for time spans ranging from 2 to 10 h. Mechanical properties including compression strength, modulus of elasticity, modulus of rupture, Janka hardness, impact bending strength, tension strength perpendicular to grain, tension strength parallel to grain, shear strength, and cleavage strength of heat-treated samples were determined. Maximum reduction values of 34.12, 28.40, and 26.37% were found for impact bending strength, tension strength parallel to grain, and cleavage strength for the samples exposed to 180°C for 10 h, respectively. Overall, the results showed that treated samples had lower mechanical properties than those of the control samples. Statistically significant difference was determined (P = 0.05) between mechanical properties of the control samples and those treated at 180°C for 10 h.

Keywords:

• Heat treatment
• Mechanical properties
• Rowan

Notes

^a Number of samples used in each test is 20.

^b Avg = average; ±s = standard deviation; s² = variance; V = coefficient of variation; N = number of samples used in each test.

^c Homogeneity groups: the same letters (A, B, C, D, E, F, G, H) in each column indicate that there is no statistical difference between the samples according to the Duncan's multiply range test at P < 0.05.

Comparisons were made between each control and its test.