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Öğe Ağaç malzeme yüzeylerine uygulanan poliüretan verniklerin parlaklığına ısıl işlem yöntemi ve işlem sıcaklığının etkisi(2022) Koç, Erol; Pelit, HüseyinBu çalışmada, farklı yöntemlerle ve farklı sıcaklık seviyelerinde ısıl işlemli ağaç malzeme yüzeylerine uygulanan poliüretan verniklerin parlaklık özellikleri incelenmiştir. Kayın (Fagus sylvatica L.) ve sarıçam (Pinus silvestris L.) odunu örnekleri üç farklı yöntem (ThermoWood, yağlı işlem ve sıcak hava) ve üç farklı sıcaklık (170 °C, 190 °C ve 210 °C) uygulanarak ısıl işleme tabi tutulmuştur. Daha sonra örnek yüzeyleri endüstriyel uygulamalara göre poliüretan vernik ile kaplanmıştır. Parlaklık ölçümleri TS EN ISO 2813 esaslarına uyularak gerçekleştirilmiştir. Verniksiz örnekler için, yağlı işlem yöntemi ile ısıl işlem görmüş örneklerde daha düşük parlaklık değerleri belirlenmiştir. ThermoWood ve sıcak hava yöntemleri ile muamele edilmiş örneklerde parlaklık değerleri benzer bulunmuş ve bu örneklerde, düşük sıcaklıktaki (170 °C) ısıl işlem sonrası parlaklıklar kontrol örneklere göre artmıştır. Vernikli örneklerde ise ısıl işlem yönteminin etkisi parlaklık üzerinde önemsiz bulunmuştur. Diğer taraftan, hem verniksiz hem de vernik uygulanmış örneklerde ısıl işlem sıcaklığı artışına bağlı olarak yüzey parlaklık değerleri azalmıştır.Öğe Aşındırıcı Su Jeti Sisteminde Farklı Parametrelerle Kesilmiş Lif Levhanın Pürüzlülük Özelliklerinin İncelenmesi(2023) Pelit, Hüseyin; Yaman, ÖzkanBu çalışmada, aşındırıcı su jeti (ASJ) sisteminde farklı işleme parametreleri ile kesilen orta yoğunluklu lif levha (MDF) örneklerin kenar pürüzlülük özelliklerinin belirlenmesi amaçlanmıştır. 18, 36 ve 54 mm kalınlıklarında hazırlanmış olan lif levhalar, ASJ sistemi ile 50, 100 ve 200 mm/dk ilerleme hızı; 200, 300 ve 450 gr/dk aşındırıcı kütle akış oranı; 300 ve 380 MPa kesici sıvı basıncı uygulanarak kesilmiştir. Örneklerde kesim yüzeyi özellikleri Ra, Rq ve Rz pürüzlülük değerleri analiz edilerek belirlenmiştir. Çalışma sonuçlarına göre, lif levha kalınlığı ve ASJ ilerleme hızı artışına bağlı olarak pürüzlülük özellikleri de artmıştır. Diğer taraftan, aşındırıcı miktarı ve kesici sıvı basıncındaki artış ile pürüzlülük değerleri genel olarak azalma eğilimi göstermiştir. Ancak, örneklerin pürüzlülük özelliklerinde levha kalınlığı ve ASJ ilerleme hızı parametreleri birinci derecede öneme sahipken, aşındırıcı akış oranı ve kesici sıvı basıncı parametrelerinin daha az bir öneme sahip olduğu belirlenmiştir.Öğe THE COLOR CHANGING EFFECT OF THE MOISTURE CONTENT OF WOOD MATERIALS ON WATER BORNE VARNISHES(North Carolina State Univ Dept Wood & Paper Sci, 2012) Budakçı, Mehmet; Sönmez, Abdullah; Pelit, HüseyinOne-component semi-matte (A) and two-component shiny (B) water-borne varnishes were applied on the surface of the test panels made of Scots pine (Pinus sylvestris L.) and Eastern beech (Fagus orientalis Lipsky) with 8%, 10%, and 12% moisture content in this study. The changes in color caused by the type of wood and moisture content on the water borne varnish layers were then investigated. The change of color in the samples was determined based on the statements in ASTM D 2224. It was determined that variations in the type of wood and moisture content affected water borne varnishes adversely, and the most apparent color change was observed in the Scots pine samples with 12% moisture content when varnish type B was applied.Öğe Decay Resistance and Color Change of Pine and Beech Wood Impregnated with R. Luteum and R. Ponticum Plant Extracts(Zagreb Univ, Fac Forestry, 2021) Pelit, Hüseyin; Alkan, Ali; Yalçın, MesutIn this study, the effect of impregnation with natural extracts on decay resistance and color change of pine and beech wood was analyzed. Flowers of Rhododendron luteum and Rhododendron ponticum plants were extracted according to the decoction method and aqueous solutions were prepared at different concentration levels (2 %, 4 % and 7 %). In addition, ferrous sulfate, copper sulfate and aluminum sulfate mordants were added to the solution to improve the properties of the extracts. Then the wood specimens were impregnated with the prepared solutions. The results indicated that the effect of plant species on the mass loss of specimens exposed to T. versicolor (white-rot fungus) was insignificant. Non-mordant extracts had a slight effect on the mass loss of the specimens. However, in pine and beech specimens impregnated with mordant-added (especially ferrous sulfate-added) extracts, mass loss was significantly reduced and resistance to fungal rot was almost completely achieved. The concentration level did not have a significant effect on the mass loss of specimens treated with mordant-added extracts. After impregnation, the L* value of all specimens (especially those treated with ferrous sulfate-added extracts) decreased and the specimens darkened. The a* and b* values increased in specimens treated with nonmordant and aluminum sulfate-added extracts and these specimens tend to have a red-yellow color. The a* value decreased and the b* value increased in wood specimens treated with copper sulfate-added extracts. The green-yellow color trend of these specimens increased. Both the a* and b* values of the specimens treated with ferrous sulfate-added extracts decreased and the green-blue color tendency increased in these specimens. The increase in the concentration level positively affected the determined color changes. The total color change (Delta E*) was higher in wood specimens (especially pine) treated with ferrous sulfate-added R. ponticum extracts.Öğe Density and some mechanical properties of densified and heat post-treated Uludag fir, linden and black poplar woods(Springer, 2018) Pelit, Hüseyin; Budakçı, Mehmet; Sönmez, AbdullahThe effects of thermo-mechanical densification and heat post-treatment on air-dry density, modulus of elasticity (MOE), bending strength (MOR), and compression strength parallel to the grain (CS) of Uludag fir (Abies bornmulleriana Mattf.), linden (Tiliagrandifolia Ehrh.), and black poplar (Populus nigra L.) wood samples were investigated. Samples were densified with compression ratios of 25 and 50%, and at 100 and 140 A degrees C. Then, the heat treatment was applied to the samples at 185 and 212 A degrees C for 2 h. According to the results of the study, density of all wood samples increased together with the increase of compression ratio. Regarding compression temperature, the highest density increase was obtained at 100 A degrees C. Mechanical strength (MOE, MOR, and CS) in densified samples increased depending on compression ratio and increase of density. The highest strength increase was in black poplar samples and the lowest was in linden samples. After heat post-treatment, mechanical strength of samples decreased depending on increase in treatment temperature. However, strength values (MOR except) of samples which are 50% compressed and heat-treated were found higher than control samples.Öğe The effect of different wood varnishes on surface color properties of heat treated wood materials(Istanbul Univ, Fac Forestry, 2017) Pelit, HüseyinThis study investigates the effects of different wood varnishes on the surface color properties of heat treated wood. Samples prepared from Oriental beech (Fagus orientalis L.) and Scots pine (Pinus sylvestris L.) are subjected to heat treatment at 190, 200, and 210 degrees C for 2 h. Sample surfaces are then covered with cellulosic (SZ), synthetic (ST), polyurethane (PU), and water-based (SB) wood varnishes, and the color properties of samples are determined according to the three-dimensional CIEL*a*b* color space. Results show a decrease in the L* and b* values of samples by 64% and 70%, respectively, depending on the process temperature after heat treatment. The a* value increases by up to 96% for Scots pine samples and up to 56% for beech samples. Color values of heat treated samples change significantly after varnish is applied; L* values of all samples are reduced compared to unvarnished samples and samples are seen to darken. However, the a* value of heat treated Scots pine samples increases significantly after varnishing, while that of heat-treated beech samples at high temperatures (200 and 210 degrees C) generally decreases. Nevertheless, the b* value decreases significantly in both wood species subjected to application of PU and ST varnishes, and the total color change (Delta E*) of varnished specimens is generally higher for samples heat-treated at 200 degrees C. Results show that ST varnish has the largest effect on color change and SB varnish has the smallest effect. The use of SB varnishes is thus preferable when it is necessary to preserve the color of samples from either species following heat treatment.Öğe The effect of some chemicals on the color properties of Beech (Fagus Orientalis L.) wood(Kastamonu Univ, Orman Fak, 2017) Yıldız, Abdülkadir; Yapıcı, Fatih; Korkmaz, Mustafa; Pelit, HüseyinAim of study: Wood material has a unique color in the natural condition. The wood colorization process is necessary to provide a tonality in the wood materials used in interior design and decoration and to obtain different colors. One of the most important steps of the coloring or bleaching process is selecting appropriate chemical for wood type. The aim of this study was to determine the effect of hydrogen peroxide, ammonia, sodium silicate and acetic acid applied periodically three times on the color changes of radial and tangent sections of beech (Fagus Orientalis L.) samples. Area of study: This study was conducted at Karabuk University and Duzce University, in Turkey. Material and Methods: The color values of the samples were measured according to the CIEL*a*b* color system. Main results: As a result, the effect of cutting direction, chemical type, and application repeat on changes in the color values of beech samples was found significant. Research highlights: The maximum color change in the beech samples was determined in the radial section as cutting direction, in the application of the sodium silicate as the chemical type and it was also obtained in the third repeat as the number of applications.Öğe The effect of some chemicals on the color properties of Beech (FagusOrientalis L.) wood(2017) Yıldız, Abdülkadir; Yapıcı, Fatih; Korkmaz, Mustafa; Pelit, HüseyinÇalışmanın amacı: Doğal haldeki ağaç malzemenin kendine özgü bir rengi vardır. İç mimari ve dekorasyonda kullanılan ağaç malzemelerde renk uyumunu sağlamak veya farklı görüntüler elde etmek için çoğu zaman renklendirme ve renk açma işlemlerine ihtiyaç vardır. Renklendirme veya renk açma işleminin en önemli basamaklarından birisi ağaç türüne uygun kimyasalın seçilmesidir. Bu araştırmanın amacı, kayın (Fagus Orientalis L.) odunundan radyal ve teğet kesitte hazırlanmış örneklere belirli aralıklarla üçer kez uygulanan hidrojen peroksit, amonyak, sodyum silikat ve asetik asit kimyasallarının örneklerde meydana getirdiği renk değişimini belirlemek içindir. Çalışma alanı: Bu çalışma Karabük Üniversitesi ve Düzce Üniversitesinde gerçekleştirilmiştir. Materyal ve Yöntem: Örneklerin renk değerleri CIEL*a*b* renk sistemine göre ölçülmüştür. Sonuçlar: Araştırma sonuçlarına göre; kayın örneklerin renk değerlerindeki değişimde kesiş yönü, kimyasal çeşidi ve uygulanma tekrarı önemli bulunmuştur. Araştırma vurguları: Örneklerdeki en fazla renk değişiminin; kesiş yönü olarak radyal kesitte, kimyasal çeşidi olarak sodyum silikat uygulamasında ve uygulama sayısında ise üçüncü tekrarda olduğu belirlenmiştirÖğe THE EFFECT OF THE MOISTURE CONTENT OF WOOD ON THE LAYER PERFORMANCE OF WATER-BORNE VARNISHES(North Carolina State Univ Dept Wood & Paper Sci, 2011) Sönmez, Abdullah; Budakçı, Mehmet; Pelit, HüseyinThe test panels obtained from Scots pine (Pinus sylvestris L.) and Eastern beech (Fagus orientalis L.) were initially adjusted to have 8%, 10%, and 12% moisture content in this study. One-component semi-matte and two-component water borne varnishes were applied on the surfaces in order to investigate the effect of the type and the moisture content of the wood on the hardness and the gloss values as well as the adhesion strength of the varnishes. The hardness of the test samples was evaluated based on the standard ANS/ISO1522, the gloss based on TS.4318 EN ISO 2813, and the adhesive strength based on ASTM D-4541. The results indicated that variations in the moisture content of the wood material adversely affected the layer performance of water-borne varnishes and that the best performance was obtained for the wood with moisture contents of 8% and 10%.Öğe Effect of Water Based Varnishes Added Nano-Graphene on the Surface Properties of Beech (Fagus orientalis Lipsky) Wood(Gazi Univ, 2019) Pelit, Hüseyin; Korkmaz, MustafaIn 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.Öğe The Effects of Densification and Heat Post-Treatment on Hardness and Morphological Properties of Wood Materials(North Carolina State Univ Dept Wood & Paper Sci, 2016) Budakçı, Mehmet; Pelit, Hüseyin; Sönmez, Abdullah; Korkmaz, MustafaThis study investigated the effects of densification and heat post-treatment on the Janka hardness and microscopic structure of relatively low-density Uludag fir, linden, and black poplar woods. Wood samples were densified with compression ratios of 25% and 50% at 100 degrees C and 140 degrees C, respectively. Heat post-treatment was then applied to the samples at 185 degrees C and 212 degrees C for 2 h. The hardness in the radial and tangential directions was determined, and morphological changes in the cell structures were analyzed using scanning electron microscopy (SEM). The hardness values in the radial and tangential directions of the densified samples increased depending on the compression rate and treatment temperature. The hardness values in both directions were higher in the 50% compressed samples. For samples compressed at 140 degrees C, the hardness values were higher in the tangential direction, whereas the samples compressed at 100 degrees C were higher in the radial direction. After the heat post-treatment process, the hardness values of all samples decreased. As the treatment temperature increased, more adverse effects on the hardness was noted. According to the SEM analyses, the densification and heat post-treatment deteriorated the cell structure of the samples. The more cell deformation was observed in the samples densified at 100 degrees C with compression ratio 50% and high heat post-treatment temperature.Öğe Effects of Heat Post-Treatment on Dimensional Stability and Water Absorption Behaviours of Mechanically Densified Uludag Fir and Black Poplar Woods(North Carolina State Univ Dept Wood & Paper Sci, 2016) Pelit, Hüseyin; Budakçı, Mehmet; Sönmez, AbdullahOne of the most persistent problems with mechanically densified wood is its inherent dimensional instability. The effects of heat post-treatment on the changes in spring-back (SB), compression ratio recovery (CRR), thickness swelling (TS), and water absorption (WA) of newly-tested Uludag fir (Abies bornmuelleriana Mattf.) and black poplar (Populus nigra L.) wood samples that had been thermo-mechanically densified were investigated. Samples were densified with compression ratios of 25% and 50% with temperatures of 100 and 140 degrees C, respectively. Then, the heat post-treatment was applied to the samples at 185 and 212 degrees C for 2 h. For the two newly-tested wood types, results of the preliminary study show that SB and TS were higher at a 50% compression ratio compared with 25%. Regarding densification temperature, TS was lower in samples densified at 140 degrees C, while SB was higher. WA values were lower in compressed samples (50%) at high rates. The effect of the densification temperature on WA was insignificant. Heat post-treatment had a considerable effect on the dimensional stability and hygroscopicity of the densified Uludag fir and black poplar samples. With an increase in heat treatment temperature, the dimensional stability increased, while the hygroscopicity of densified samples decreased. As a result of heat post-treatment applied at 212 degrees C, SB, CRR, TS, and WA decreased by 88%, 85%, 79%, and 53%, respectively.Öğe Effects of Thermomechanical Densification and Heat Treatment on Density and Brinell Hardness of Scots Pine (Pinus sylvestris L.) and Eastern Beech (Fagus orientalis L.)(North Carolina State Univ Dept Wood & Paper Sci, 2015) Pelit, Hüseyin; Sönmez, Abdullah; Budakçı, MehmetThe effects of thermomechanical densification (TMD) and heat treatment on density and Brinell hardness of Scots pine (Pinus sylvestris L.) and Eastern beech (Fagus orientalis L.) woods were investigated. Samples were densified using a specially designed hydraulic press with target compression ratios of 20 and 40%, and at 110 degrees C and 150 degrees C. Then, the heat treatment was applied to the samples at three different temperatures. To determine whether the changes occurred because of technological properties, tests of Brinell hardness and air-dry density were conducted. Increases of 42 and 35% were obtained for the density of Scots pine and beech samples, respectively. After the densification process, increases in radial and tangential hardness values were obtained. Decreases were observed in the density and hardness values of the samples because of the increase in temperature during heat treatment. After heat treatment, there were 4 and 5% decreases in the respective densities of Scots pine and beech, and decreases in their radial and tangential hardness values.Öğe Effects of ThermoWood (R) Process Combined with Thermo-Mechanical Densification on some Physical Properties of Scots Pine (Pinus sylvestris L.)(North Carolina State Univ Dept Wood & Paper Sci, 2014) Pelit, Hüseyin; Sönmez, Abdullah; Budakçı, MehmetEffects of heat treatment on some physical properties of Scots pine (Pinus sylvestris L.) wood densified using a thermo-mechanical method were determined. Samples were densified in the radial direction with a specially designed hydraulic press machine with target compression ratios of 20% and 40%, and at 110 degrees C and 150 degrees C. Then, heat treatment was applied to the samples during 2 h at three different temperatures (190 degrees C, 200 degrees C, and 210 degrees C). In order to determine the changes occurring in physical properties, tests of actual compression ratio, spring-back, compression ratio recovery effect, swelling (TS 4084) in compression direction (radial), and density (TS 2472) were conducted. According to results of the research, at the same target compression ratio (20% or 40%), higher actual compression ratio and density increase were observed in the samples densified at 110 degrees C in comparison to those densified at 150 degrees C. While an increase of 42% in density was being obtained, small rates of decreases up to 4% were observed after heat treatment. Application of heat treatment and increase of treatment temperature significantly influenced dimensional stability of densified Scots pine. Furthermore in comparison to samples without heat treatment, effects of compression ratio recovery were reduced by 80%.Öğe Farklı yöntemlerle ısıl işlem uygulanmış ağaç malzemelerde yoğunluk ve eğilme direncinin belirlenmesi(2022) Pelit, Hüseyin; Bayraktar, SelçukBu çalışmada, ağaç malzemelerin hava kurusu yoğunluk ve eğilme direnci üzerine farklı yöntem ve sıcaklık koşullarında uygulanan ısıl işlemlerin etkisi analiz edilmiştir. Sarıçam (Pinus silvestris L.) ve kayın (Fagus sylvatica L.) odunu örnekleri ThermoWood, yağlı işlem ve sıcak hava yöntemleri kullanılarak üç farklı sıcaklıkta (170 °C, 190 °C ve 210 °C) ayrı ayrı ısıl işleme tabi tutulmuştur. Deney örneklerinin yoğunluk ve eğilme direnci sırası ile TS 2472 ve TS 2474 esaslarına uyularak belirlenmiştir. Araştırma sonuçlarına göre, ısıl işlem yöntemi ve işlem sıcaklığındaki farklılaşma ahşap örneklerin yoğunluk ve eğilme direnci değerleri üzerinde önemli bulunmuştur. Isıl işlem yöntemi açısından, her iki ağaç türü için en yüksek yoğunluk ve eğilme direnci yağlı ısıl işlem görmüş örneklerde elde edilmiştir. Ayrıca, sıcak hava yöntemine göre ThermoWood yöntemi ile işlem görmüş örneklerde daha yüksek direnç değerleri bulunmuştur. Tüm yöntemler için, ısıl işlem sıcaklığındaki artışa bağlı olarak ahşap örneklerde yoğunluk ve eğilme direnci değerleri azalmıştır. Sıcaklık artışından kaynaklanan yoğunluk ve direnç kayıpları yağlı ısıl işlem yönteminde en az seviyede iken, sıcak hava yönteminde en fazla orana sahiptir.Öğe Influence of Densification on Mechanical Properties of Thermally Pretreated Spruce and Poplar Wood(North Carolina State Univ Dept Wood & Paper Sci, 2019) Pelit, Hüseyin; Yorulmaz, RamazanThe effects of mechanical densification on density, Brinell hardness, bending strength (MOR), modulus of elasticity (MOE), and compression strength (CS) of thermally pretreated spruce (Picea orientalis) and poplar (Populus nigra) wood samples were investigated. Thermal treatment was applied on the wood samples at four different temperatures (140 degrees C, 160 degrees C, 180 degrees C, and 200 degrees C) and two different durations (7 h and 9 h) under atmospheric pressure. Wood samples were then densified by compression at a temperature of 150 degrees C to two degrees (20% and 40%) of compression. The results indicated that the density, hardness, and MOR values of both compressed and non-compressed thermally pretreated spruce and poplar samples decreased with increasing treatment temperature and duration. At temperatures below 200 degrees C, the MOE was generally increased in thermally pretreated samples. However, the MOE was reduced in thermally pretreated samples at 200 degrees C compared to the untreated samples. Additionally, all thermal pretreatments increased CS values in compressed and non-compressed wood samples. The CS tended to decrease in thermally pretreated samples (especially 40% compressed) at 200 degrees C. After the densification, all of the strength properties tested in thermally pretreated samples increased significantly depending on the increase in compression ratio.Öğe Kayın (Fagus orientalis Lipsky) Odununun Yüzey Özelliklerine Nano-Grafen Katkılı Su Bazlı Verniklerin Etkisi(2019) Pelit, Hüseyin; Mustafa, KorkmazBu çalışmada, nano-grafen (NG) ile modifiye edilmiş su bazlı vernik uygulanan kayın (Fagus orientalis Lipsky) odunu örneklerinin yüzey parlaklık, pürüzlülük, sertlik ve renk değişimi ile vernik yapışma direnci özellikleri araştırılmıştır. Su bazlı vernik içerisine, ağırlıkça %0.25, %0.50 ve %1 NG eklenmiş ve ardından hazırlanan vernik çözeltisi örnek yüzeylerine uygulanmıştır. Araştırma sonuçlarına göre, vernik içerisine eklenen NG miktarındaki artışa bağlı olarak örneklerin yüzey parlaklık değerleri azalmış, pürüzlülüğü ise bir miktar artmıştır. Diğer taraftan, NG miktarındaki artış sonucu kayın örneklerdeki vernik yapışma direncinde %25’e kadar önemli artışlar sağlanmıştır. Vernik uygulamalarından sonra örneklerin yüzey sertlik değeri artmıştır. Ancak, sertlik artışında NG’in etkisi öngörülenin aksine önemsiz bulunmuştur. Ayrıca, NG katkısı ve miktarındaki artış sonucu örneklerin L*, a* ve b* renk değerleri önemli oranda azalmıştır. Örnekler koyulaşmış ve yeşil-mavi renk eğilimi artmıştır. Sonuç olarak, su bazlı vernikte yüksek yapışma direncinin sağlanmasında ve ağaç malzemenin koyu tonlarda renklendirilmesinde NG’in değerlendirilmesi önerilebilir.Öğe Resistance of mechanically densified and thermally post-treated pine sapwood to wood decay fungi(Springer Japan Kk, 2017) Pelit, Hüseyin; Yalçın, MesutThis paper evaluated the density and biological resistance of pinewood samples modified with thermo-mechanical densification and thermal post-treatment. The samples were densified with 20 and 40% compression ratios at either 110 or 150 A degrees C. The thermal post-treatment was then applied to the pine samples at 185 and 212 A degrees C for 2 h. These samples were exposed to white-rot (Trametes versicolor) and brown-rot (Coniophora puteana) fungi for twelve weeks and the resulting mass loss was determined. In the densified samples, the effects of the compression ratio on T. versicolor-initiated mass loss and of the compression temperature on C. puteana-initiated mass loss were found to be significant. The mass loss was less in the samples compressed at 150 A degrees C with the 40% ratio, while the highest mass loss was observed in the undensified samples. In the thermally post-treated samples, the resistance to both decay fungi was significantly increased with the increase of the treatment temperature. The mass loss in the thermally post-treated samples at 212 A degrees C after T. versicolor and C. puteana fungi testing was reduced by 73 and 67%, respectively. However, the effect of the densification processes on decay resistance in the thermally post-treated samples was insignificant.Öğe Roughness, Wettability, and Morphological Properties of Impregnated and Densified Wood Materials(North Carolina State Univ Dept Wood & Paper Sci, 2023) Pelit, Hüseyin; Arısüt, UmuthanThe effects of pre-impregnation on surface roughness, wettability, and morphological structure of densified aspen and fir wood were investigated. Wood specimens were impregnated with paraffin, linseed oil, and styrene after pre-vacuum treatment. The impregnated specimens were densified using compression ratios of 20% and 40% at 120 degrees C, 150 degrees C, and 180 degrees C. The roughness decreased and the contact angle increased in all impregnated specimens (undensified and densified). Compared to paraffin and linseed oil-impregnated specimens, lower roughness and higher contact angle were found in styrene-impregnated specimens. After densification, the roughness and wettability of the wood specimens decreased. More successful results (lower roughness and higher contact angle) were generally obtained in specimens densified with high compression ratio (40%). In both untreated and impregnated specimens, the contact angle increased with increasing compression temperature. While the effect of compression temperature on the roughness of the fir specimens was not significant, the roughness of the aspen specimens (especially styrene-impregnated) decreased with the increase in temperature. Scanning electron microscopy observations indicated that impregnation agents (especially styrene) clung to wood cell walls and partially or completely filled the lumens. This was positively correlated with the determined roughness and wettability. Pre-impregnation facilitated wood densification without significant cell deformations.Öğe Surface properties of tannin-impregnated and varnished beech wood after exposure to accelerated weathering(Wiley, 2017) Yalçın, Mesut; Pelit, Hüseyin; Akçay, Çağlar; Çakıcıer, NevzatThe aim of this study was to determine selected surface properties of varnished beech wood impregnated with natural extracts after exposure to accelerated weathering. Beech wood samples were impregnated with aqueous solutions of 5 and 10% mimosa (Acacia mollissima) and quebracho (Shinopsis lorentzii) tannins. After weathering, colour changes (Delta L*, Delta a*, b*, and Delta E*) in addition to scratch resistance and surface hardness values were calculated and evaluated. As a result of the weathering process, greater colour changes (Delta E*) were detected in the beech wood samples impregnated with tannins compared with the unimpregnated control samples. The least colour change occurred in the Tanalith-E-impregnated samples. Total colour change was adversely affected with tannin impregnation after the weathering processes. In terms of surface hardness and scratch resistance, the highest values were observed in the mimosa-solution-impregnated and control samples. Furthermore, it was found that scratch resistance and hardness values tended to increase during the first period of weathering and decreased thereafter. Regarding surface properties, the best results were obtained when polyurethane varnish was employed compared with the other varnish types.
