Ayata, Ümit; Peker, Hüseyin; Ulay, Göksel; Çamlıbel, Osman; Atilgan, Abdi

It is known that blue stain causes a loss of price value for Scots pine wood in the wood trade due to the visual defects it creates. In this study, color parameters [red color tone (a*), lightness (L*) value, yellow (b*) color tone, tone angle (h°) value, and chroma (C*) value], whiteness index (WI*) values, and glossiness measurements [at angles of 20°, 60°, and 85°] were compared in Scots pine (Pinus sylvestris L.) wood with normal and blue rot conditions. According to the color parameters obtained, it was determined that the L* value decreased by 11.43%, a* by 79.95%, b* by 28.86%, and C* by 32.75%, while the h° value increased by 17.74%. With the blue coloration, decreases were observed in the 20° glossiness values measured in the ⃦ and ⊥ directions, while increases were observed in the 60° and 85° glossiness values measured in the ⃦ and ⊥ directions. With the blue coloration, decreases of 12.86% in the ⊥ direction and 29.87% in the ⃦ direction in the WI* values were observed. According to these results, it was determined that the wood material with the blue coloration disease had a darker color.

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Akter, Mete; Ulay, Göksel; Peker, Hüseyin; Çakıcıer, Nevzat; Atilgan, Abdi; Ayata, Ümit

Pendulum hardness test is important for determining the mechanical durability and long-term performance of the film layer formed on the surface of wood thermally treated at high temperatures and coated with water-based varnish (WBV). In this study, the effect of artificial weathering conditions on the pendulum hardness (König method) of ash (Fraxinus angustifolia Vahl.) wood samples varnished with polyurethane modified WBV was investigated. The samples were thermally treated under two conditions (190°C for 1.5 h and 212°C for 2 h) and compared with untreated control samples. The samples were exposed to artificial weathering conditions (for periods of 0, 168, 336 and 504 h). Pendulum hardness values were measured at the end of each weathering period. According to the results, increases in hardness values were observed in both heat-treated and untreated ash wood samples treated with varnish after weathering. In the varnished samples treated at 212°C for 2 h, the post-weathering hardness increases were lower compared to the samples treated at 190°C for 1.5 h and the control group. Additionally, analysis of variance for the pendulum hardness test, heat treatment, weathering time and their interaction were determined to be statistically significant. The significant increases in hardness values observed in the unweathered samples highlight the importance of the wood, varnish, and weathering process.

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