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- MakaleYalnız künye2026Scopus SJRQ2Weathering effects on pendulum hardness, and pull-off adhesion testing of water-based varnish on thermally treated iroko wood
Ulay, Göksel; Akter, Mete; Çakıcıer, Nevzat; Ayata, Ümit
This study evaluated the effects of different weathering durations (168, 336, and 504 h) on surface hardness and adhesion strength of both heat-treated (1.5 h at 190 °C and 2 h at 212 °C) and untreated iroko (Chlorophora excelsa) wood surfaces after application of water-based varnish (WBV). Pendulum hardness (s) and pull-off adhesion (MPa) tests were performed after weathering. According to the results, in the untreated control group, hardness increased from 30 s to 45 s after 504 h of weathering, showing a 48% increase. In the samples treated at 190 °C, hardness increased from 25 s to 41 s after 504 h, showing a 61% increase. The highest increase was observed in the samples treated at 212 °C. Here, the hardness increased from 23 s to 44 s, representing a 91% increase after 504 h of weathering. The highest initial surface adhesion strength (5.30 MPa) was obtained in the unheated samples; however, this value decreased significantly after weathering. Although the initial adhesion strength was lower in the heat-treated samples, those treated at 212 °C for 2 h exhibited more stable weathering performance. The results show that the acceleration of weathering and the application of heat significantly affect the effectiveness of the varnish coating.
- MakaleYayıncıda açık erişim2026Scopus SJRQ3Effects of Artificial Weathering Resistance on the Hardness Value of Ash Wood Surfaces Coated with Polyurethane Modified Water-Based Varnish after Heat Treatment
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.
- MakaleAçık Erişim2023The effects of artificial weathering on the pendulum hardness of chestnut wood applied with polyurethane varnish after heat treatment; [Isıl işlem sonrası poliüretan vernik uygulanmış kestane odununda salınımsal sertlik üzerine yapay yaşlandırmanın etkileri]
Ulay, Göksel; Ayata, Ümit
The effects of artificial weathering (576 h) on the pendulum hardness values of Anatolian chestnut (Castanea sativa Mill.) wood applied with polyurethane varnish (PU) after heat treatment at 190°C for 1.5 h and at 212°C for 2 h were investigated. The results revealed that heat treatment, weathering period, and interaction were significant. The hardness values of the heat-treated materials were higher than those of the non-heat-treated test samples. The highest hardness value was determined in the un-weathered group of the test samples that were heat-treated at 190°C for 1.5 h while the lowest value was determined in the group that was heat-treated at 190°C for 1.5 h and weathered for 432 h. The highest reduction rates after weathering were obtained on samples that were heat-treated at 190°C for 1.5 h, followed by heat-treated at 212°C for 2 h and non-heat-treated. It was observed that the heat treatment application caused different pendulum hardness values in chestnut wood samples covered with polyurethane varnish.
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İncele - MakaleAçık Erişim2023Scopus SJRQ3Investigation of Use of Linden (Tilia tomentosa Moench.) Wood with UV System Varnish Application IN INDOOR Parquet Flooring
Ayata, Ümit; Esteves, Bruno; Domingos, Idalina; Ferreira, José; Tuncay Efe, Fatih; Türk, Mutlu; Çakicier, Nevzat; Gürleyen, Levent; Peker, Hüseyin
Linden wood is used in the making of musical instruments, agricultural hand tools, and in the furniture sector. In this study, the changes in glossiness (parallel (//) and perpendicular (⊥) to the fibers at 20°, 60°, and 85°, the pull-off adhesion test, color parameters (CIEL) and pendulum hardness (König method) of two different UV curable varnishes applied to linden (Tilia tomentosa Moench.) according to industrial application techniques and exposed to artificial weathering were investigated. According to the research results, while L*, ΔH*, and h° decreased with increasing weathering time in both varnish layers, ΔC*, b*, ΔE*, a*, and C* rose. The pendulum hardness grew for Method B but dwindled for Method A. A decrease was found in the adhesion tests for both varnish methods after artificial weathering. The glossiness was generally reduced due to artificial weathering for all the angles and for both directions, with the exception of 85º in Method A. The variance analysis and homogeneity groups showed that the changes in the adhesion, pendulum hardness, L*, a*, h°, C*, perpendicular and parallel to the fibers for 60° and 85° were found to be significantly different with artificial weathering for both methods.
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İncele - MakaleAçık Erişim2021Scopus SJRQ2Effect of accelerated ageing on some surface properties of uv-coated hackberry (Celtis australis l.) wood parquet
Ayata, Ümit; Esteves, Bruno; Gürleyen, Levent; Çakicier, Nevzat; Ferreira, J.O.S.É.; Domingos, Idalina; Türk, Mutlu
The importance of UV-curable coatings is currently increasing. In the parquet industry, where UV systems are applied, it is beneficial to investigate new tree species as potential raw materials. This study was carried out to determine the effect of accelerated ageing on some surface properties of hackberry (Celtis australis L.) wood treated with UV system parquet varnish. UV system parquet varnishes were applied to hackberry wood surfaces in three and five layers, according to the requirements of industrial applications. The varnished surfaces were then exposed to UV rays for 252 and 504 h using UVA-340 lamps in a QUV ageing device. Glossiness, colour parameters, pendulum hardness and adhesion strength (pull-off) (MPa) were determined for the coated samples before and after ageing, and the results for the aged and unaged test samples were compared. Analysis of variance showed that the results were significant for all tests. The results for all tests varied by ageing time.
AtıfScopus5WoS4OpenAlex3İncele - MakaleAçık Erişim2021Scopus SJRQ2Determination of pendulum hardness (KÖnig method) values against artificial weathering in water-based varnishes applied to some wood species after heat treatment (thermowood)
Ayata, Ümit; Çakicier, Nevzat
Scots pine, beech, and oak are the most important tree species in the furniture sector in Turkey. In this study, the aim is to determine pendulum hardness (König method) values against artificial aging in water-based varnishes applied to some wood species after heat treatment. For this purpose, Scots pine (Pinus sylvestris L.), sessile oak (Quercus petreae L.), and Eastern beech (Fagus orientalis L.) wood samples were heat-treated at 190 °C for 2 h and at 212 °C for 1–2 h according to the ThermoWood method. Later, one-and two-component water-based varnishes (WBVOne-Comp. and WBVTwo-Comp.) were applied to the material surfaces in accordance with the manufacturer’s recommendations for layer thickness for industrial applications. The materials were exposed to UV light using UV-A 340 nm fluorescent lamps for 144, 288, and 432 h in a QUV accelerated weathering tester. After these weathering periods, pendulum hardness values were determined. It was found that hardness values increased after weathering, and that WBVTwo-Comp. gave higher values than WBVOne-Comp..
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