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, wereb 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.

The objective of this study was to determine adhesive strength of particleboard and medium density fiberboard (MDF) finished with two types of paints. Samples were coated using cellulosic and polyurethane based paints. Adhesion strength and coating layer thickness of each sample were measured using pull-off testing method and PosiTector equipment, respectively. The highest adhesion strength value of 3.62MPa was found for MDF samples coated with paint. Based on the statistical analysis type of substrate significantly influenced overall adhesion strength of the samples while type and layer thickness of paint as well as number of layers applied to the surface of specimens have not affected significantly adhesion resistance of the panels used in this work. It appears that pull-off test can effectively be used to determine and evaluate adhesion strength of the samples considered in the experiments.

The aim of this study is to enhance the coating adhesion strength by optimizing the air plasma application parameters. Air-plasma treatment parameters were selected as working distance, treatment speed and pressure, while material type parameters were determined as low mean density fiberboard (MDF-1) and high-density mean fiberboard (MDF-2). Due to the low adhesion strength in water-based paint applications compared to other types of paint, water-based paint was applied to these samples. Taguchi orthogonal design and analysis of variance (ANOVA) were applied to investigate the significant parameters on the adhesion strength. Desirability function was used to determine the optimum factor levels. According to experimental design results, working distance, treatment speed, and pressure values of 8.82 mm, 60 mm/s, and 1.10 bar were determined as optimum plasma treatment parameters for MDF-1, respectively. Corresponding values for MDF-2 were 9.19 mm, 60 mm/s, and 1.06 bar. The improvement in adhesion strength was evaluated as 22% increase for MDF-1 and 16% increase for MDF-2.

Furniture from wood material is exposed to various external effects. Impact has negative influence on these materials. Surface treatment is effective on wood material’s durability. This may change due to layers of paint and the property of the paint used on the material. The aim of this study is to determine the differences by investigating the deformations occurring on Medium Density Fiberboard (MDF) with various surface treatments due to impact. Determination of the deformation values were performed by pendulum hardness test and rapid deformation test on MDF using polyurethane and cellulosic paints with different number of application layers. Impact tester was used for determining the effect of rapidly deforming sudden impacts. Pendulum hardness tester was used to determine the layer hardness of the surfaces. Statistical assessment was performed for determining and revealing the impacts. As result of the study, paint type, layer thickness and the interaction between them were significant. Highest layer hardness values for cellulosic paint application type 1 and polyurethane paint type 2 were 241,667 s and 222,133 s respectively. According to rapid deformation test it was determined that polyurethane paint application had better results than cellulosic paint application.