The Effects of Densification and Heat Post-Treatment on Hardness and Morphological Properties of Wood Materials

The Journal of the Korean Wood Science and Technology (JKWST) launched in 1973 as an official publication of the Korean Society of Wood Science and Technology has been served as a core of knowledges on wood science and technology.

In this study, surface glossiness, roughness, hardness, color change, and varnish adhesion resistance properties of beech (Fagus orientalis Lipsky) wood samples coated with nano-graphene (NG) modified water based varnishes were investigated. 0.25%, 0.50% and 1% by weight of NG were added to the water-based varnish and the prepared solution was applied to the samples surfaces. According to the results of the research, the surface glossiness of the samples decreased and the roughness values increased slightly due to the increase of NG in the varnish. On the other hand, the increase in the amount of NG provided significant increases in varnish adhesion resistance up to 25%. The surface hardness value of beech samples increased up to 13% after varnishing. However in contrast to the predicted, effect of NG on hardness values was found to be insignificant. On the other hand, the values of L*, a* and b* decreased significantly with the increase of NG ratio. The samples were darkened and the green-blue color tendency of the samples increased. As a result, it may be recommended that NG addition can be prefer in the water based varnishes to provide high adhesion strength and in the surface darkening process.

The relationship between the thermal conductivity and some mechanical properties of Uludağ fir and black poplar specimens were determined based on related standards. It was hypothesized that thermal conductivity can be used as a predictor for wood properties. The hot plate test method was used as a thermal conductivity testing method. The density, compression strength, modulus of rupture, and modulus of elasticity values were also measured. Pearson’s correlation coefficient was determined and both linear and multiple regression analyses were performed to estimate the relationship between the parameters. The correlation between the thermal conductivity and density values was strong, which was consistent with past findings. Also, there was a strong correlation between the thermal conductivity, modulus of rupture, and modulus of elasticity, while the compression strength and thermal conductivity had a moderate correlation. The regression equations and test graphs were also determined and shown. Overall, it can be claimed that the thermal conductivity could be used for predicting the density and mechanical properties of wooden materials.

Exposure to airborne dust and noise during woodworking operations pose serious occupational health risks. This study investigated the influence of key cutting parameters—rotational speed, feed rate, tooth count, and dust collection system status—on PM10 concentration and noise levels during circular sawing. Experimental measurements were conducted on six materials, including solid wood species (Scots pine, Oriental beech) and engineered wood products (plywood, medium-density fiberboard, oriented strand board, and particleboard). The collected data were analyzed using response surface methodology (RSM) to optimize cutting conditions, aiming to minimize emissions while maintaining operational efficiency. The results indicated that both material type and processing parameters notably affected dust and noise levels. Optimized cutting settings led to a measurable reduction in exposure, offering practical guidelines for improving workplace safety in the woodworking and furniture industries. This study contributes to the development of safer and more sustainable machining practices by addressing the hidden risks associated with dust and noise pollution.