İç ve dış ortam koşullarında güneş ışınlarına maruz kalan odunun foto-degradasyonu
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Dosyalar
Tarih
2024
Yazarlar
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Dergi ISSN
Cilt Başlığı
Yayıncı
Bursa Teknik Üniversitesi, Lisansüstü Eğitim Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Çalışmanın amacı, endüstride farklı kullanım alanlarında tercih edilen 27 farklı odun türünün iç ortam (pencere yakınındaki kullanım yerleri) ve dış ortam koşullarında maruz kalabileceği güneş ışığına karşı dayanıklılığının belirlenmesi ve bu tür ahşap malzemeden üretilen ürünlere ekonomik değer kazandırabilecek bilgilerin elde edilmesidir. Yaşlandırılan örneklerin renk, yüzey pürüzlülük ölçümleri, yüzey kimyası (ATR-FTIR) ve makroskopik açıdan değerlendirilmesi periyodik olarak 1 yıl boyunca gerçekleştirilmiştir. Sonuçlara göre dış ortam yaşlandırmasına bırakılan örneklerin yüzeyindeki renk değişimi 3. aydan itibaren gözlenebilir seviyede olmuş ve yerli ağaç türü odunları egzotik odun türlerine kıyasla çok daha fazla yüzey koyulaşması ve renk değişimi göstermiştir. Dış ortam yaşlandırmasında, egzotik türlerden en az renk değişimine sahip odun türü venge olurken en fazla renk değişimi ayousda olmuştur. Yerli türlerden en az renk değişimi ceviz ve karaağaçta görülürken en fazla renk değişimi kavakda bulunmuştur. İç ortam yaşlandırmasında egzotik türlerden en az renk değişimine sahip odun türü iroko olurken en fazla renk değişimi vengede görülmüştür. Yerli türlerden en az renk değişimi kirazda görülürken en fazla renk değişimi sarıçamda bulunmuştur. İç ortam koşullarının yol açtığı fotodegradasyon dış ortam koşullarına göre daha az bulunmuştur. Ayrıca, yüzey pürüzlülüğü ve mikro çatlakların, özellikle dış ortam koşullarında, hava koşullarıyla birlikte arttığı bulunmuştur. FTIR spektrumları, özellikle asetil ve lignin gruplarında kimyasal değişiklikleri ortaya çıkarmıştır. Çalışmada, iç ve dış ortam koşullarının, ağaç türü odununun ve nem koşullarının incelenen parametreler üzerinde önemli bir role sahip olduğu bulunmuştur. Dış ortamda bekletilen örneklerde 9. Aydan sonra önemli ölçüde koyulaşma, yüzeylerde küf oluşumu ile çatlak oluşumu gözlenmiştir. İç ortamda ise, herhangi bir çatlak, küf oluşumu görülmemiş, örneklerde hafif bir renk değişimi gözlnemiştir. Çalışmada iç ortam koşullarının dahi, odun yüzeylerinde renk değişimine neden olduğu görülmüştür. Bundan dolayı ahşap örneklerin yüzeyine bir koruma veya üst yüzey işlemi uygulaması yapılması gereklidir. Dış ortamda kullanılacak ahşap malzemenin doğal dayanıklı bir tür olsa dahi mutlaka bir koruyucu işlemden veya üst yüzey uygulamadan geçirilmesi gereklidir. Aksi durumda yüzeylerde önemli renk değişimleri, küf mantarları ve çatlak oluşumu görülebilecektir.
The aim of the study is to determine the resistance of 27 different wood species, which are preferred in different use class in the industry, against solar rays that they may be exposed to in indoor (use areas near windows) and outdoor conditions. It was also aimed to get knowledge that can add economic value to wood products produced from these wood species. Color, surface roughness measurements, surface chemistry (ATR-FTIR) and macroscopic evaluation of the weathered samples were carried out periodically for a year. According to the results, the color change on the wood surfaces exposed to outdoor weathering was observable during the first 3 months, and native wood species showed much more surface darkening and color change compared to exotic wood species. In outdoor weathering, the wood species with the least color change among exotic species was wenge, while the most color change was in ayous. Among the native species, the least color change was seen in walnut and elm, while the most color change was found in poplar. Among exotic species, iroko had the least color change in indoor conditions, while the most color change was seen in wenge. Among the native species, the least color change was seen in cherry, while the most color change was found in Scots pine. Photodegradation caused by indoor conditions was found to be less than outdoor conditions. Additionally, surface roughness and microcracks were found to increase with weather conditions, especially in outdoor conditions. FTIR spectra revealed chemical changes, especially in acetyl and lignin groups. In the study, it was found that the indoor and outdoor conditions, wood species and humidity conditions had an important role on the parameters examined. Significant darkening, mold formation and crack formation on the surfaces were observed after the 9th month in the samples kept outdoors. In the indoor environment, no cracks or mold formation were observed, and a slight color change was common in the samples. The study showed that even indoor conditions caused color change on the wood surfaces. Therefore, it is necessary to apply a protection or surface treatment to the surface of wood samples. Even if the wooden material to be used outdoors is a naturally durable species, it must be subjected to a protective treatment or surface application. Otherwise, significant color changes, mold and crack formation may occur on the surfaces.
The aim of the study is to determine the resistance of 27 different wood species, which are preferred in different use class in the industry, against solar rays that they may be exposed to in indoor (use areas near windows) and outdoor conditions. It was also aimed to get knowledge that can add economic value to wood products produced from these wood species. Color, surface roughness measurements, surface chemistry (ATR-FTIR) and macroscopic evaluation of the weathered samples were carried out periodically for a year. According to the results, the color change on the wood surfaces exposed to outdoor weathering was observable during the first 3 months, and native wood species showed much more surface darkening and color change compared to exotic wood species. In outdoor weathering, the wood species with the least color change among exotic species was wenge, while the most color change was in ayous. Among the native species, the least color change was seen in walnut and elm, while the most color change was found in poplar. Among exotic species, iroko had the least color change in indoor conditions, while the most color change was seen in wenge. Among the native species, the least color change was seen in cherry, while the most color change was found in Scots pine. Photodegradation caused by indoor conditions was found to be less than outdoor conditions. Additionally, surface roughness and microcracks were found to increase with weather conditions, especially in outdoor conditions. FTIR spectra revealed chemical changes, especially in acetyl and lignin groups. In the study, it was found that the indoor and outdoor conditions, wood species and humidity conditions had an important role on the parameters examined. Significant darkening, mold formation and crack formation on the surfaces were observed after the 9th month in the samples kept outdoors. In the indoor environment, no cracks or mold formation were observed, and a slight color change was common in the samples. The study showed that even indoor conditions caused color change on the wood surfaces. Therefore, it is necessary to apply a protection or surface treatment to the surface of wood samples. Even if the wooden material to be used outdoors is a naturally durable species, it must be subjected to a protective treatment or surface application. Otherwise, significant color changes, mold and crack formation may occur on the surfaces.
Açıklama
Anahtar Kelimeler
Ormancılık ve Orman Mühendisliği, Forestry and Forest Engineering, Fotokimya, Photochemistry, Sürdürülebilir ormancılık, Sustainable forestry
