Nevzat Çakicier

The Effects of Heat Treatment on the Physical Properties and Surface Roughness of Turkish Hazel (Corylus colurna L.) Wood

Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L.) wood were examined. Samples obtained from Kastamonu Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for different durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements, using the stylus method, were made in the direction perpendicular to the fiber. Four main roughness parameters, mean arithmetic deviation of profile (Ra), mean peak-to-valley height (Rz), root mean square roughness (Rq), and maximum roughness (Ry) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was determined (p = 0.05) between physical properties and surface roughness parameters (Ra,Rz, Ry, Rq) for three temperatures and three durations of heat treatment. The results showed that the values of density, swelling and surface roughness decreased with increasing temperature treatment and treatment times. Turkish Hazel wood could be utilized successfully by applying proper heat treatment techniques without any losses in investigated parameters. This is vital in areas, such as window frames, where working stability and surface smoothness are important factors.

Effects of heat treatment on the adhesion strength, pendulum hardness, surface roughness, color and glossiness of Scots pine laminated parquet with two different types of UV varnish application

The objective of this study was to investigate the surface properties of a UV-system applied on laminated parquet made with untreated and heat treated wood (ThermoWood). In this study, wood specimens prepared from Scots pine (Pinus sylvestris) wood were heat treated according to ThermoWood method at 190oC for 2 hours and at 212oC for 1 and 2 hours adhesion strength, pendulum hardness, surface roughness, colour and glossiness were determined. The UV-system was applied in two different types according to manufacturer recommendations. Results show that lightness and glossiness decreases and red colour tone increases with heat treatment. Pendulum hardness increased initially, decreasing afterwards with the intensity of the heat treatment. Tests showed that adhesion generally decreased with heat treatment. No significant differences were found for the surface roughness although a slight decrease was observed.