Investigation of High-frequency Vacuum Drying on Physical and Mechanical Properties of Common Oak (Quercus robur) and Common Walnut (Juglans regia) Lumber

In conventional drying kilns, the drying of especially thick lumber is not ideal in terms of drying quality and drying time. Therefore, it is important to dry thick and dense lumber by high-frequency electromagnetically heated vacuum drying. In this study, common oak (Quercus robur) and common walnut (Juglans regia) selected from local sources used in rifle stock were used as experimental material. These materials were technologically examined by drying the timber for a short time using a fully automated, high frequency vacuum (HF + V) drying kiln. Physical and mechanical properties of these tree species were compared after air drying and HF + V drying processes. There were no significant changes in physical properties. However, the mechanical properties such as bending strength, modulus of elasticity, compression strength, and dynamic bending strength were decreased. According to these results, non-overloaded areas like rifle stock can use high frequency vacuum drying as the preferred drying method compared to conventional drying methods.