Hüseyin Pelit - Academia.edu (original) (raw)

Papers by Hüseyin Pelit

Gazi Üniversitesi Fen Bilimleri dergisi, Nov 1, 2023

Bu çalışmada, aşındırıcı su jeti (ASJ) sisteminde kesilmiş orta yoğunluklu liflevha (MDF) malzeme... more Bu çalışmada, aşındırıcı su jeti (ASJ) sisteminde kesilmiş orta yoğunluklu liflevha (MDF) malzemenin kenar pürüzlülük özellikleri üzerine seçilmiş işleme parametrelerinin etkisi incelenmiştir. Örneklerde Ra, Rq ve Rz pürüzlülük değerleri analiz edilmiş ve endüstriyel uygulamalara yönelik öneriler sunulmuştur. / In this study, the effect of selected processing parameters on the edge roughness properties of medium density fiberboard (MDF) material cut in the abrasive water jet (AWJ) system was examined. Ra, Rq and Rz roughness values in the samples were analyzed and suggestions for industrial applications were presented. Şekil A: MDF örneklerin ASJ sisteminde kesilmesi ve pürüzlülük ölçümleri / Figure A:.Cutting of MDF samples in AWJ system and roughness measurements Önemli noktalar (Highlights) ➢ MDF örneklerin kesilmesinde yüksek verimliliğe sahip, düşük maliyetli, basit, temiz ve güvenilir bir teknoloji olan ASJ makinesi kullanılmıştır. / AWJ machine, which is a highefficiency, low-cost, simple, clean, and reliable technology, was used to cut the MDF samples. ➢ MDF örnekler ASJ makinesi ile farklı parametrelerde kesilmiş ve örneklerin pürüzlülük özellikleri belirlenmiştir. / MDF samples were cut with the ASJ machine at different parameters and the roughness properties of the samples were determined. ➢ Örneklerin kesim yüzeyi düzgünlüğünde seçilmiş işleme parametrelerinin etkisi önemli bulunmuştur. / The effect of selected processing parameters on the smoothness of the cutting surface of the samples was found to be significant. Amaç (Aim): Bu çalışmada, levha kalınlığı, kesici sıvı basıncı, aşındırıcı akış oranı ve ilerleme hızı faktörlerinin ASJ sisteminde kesilen MDF örneklerin pürüzlülük özelliklerine etkisinin belirlenmesi amaçlanmıştır. / In this study, it was aimed to determine the effects of board thickness, cutting liquid pressure, abrasive flow rate and feed rate factors on the roughness properties of MDF samples cut in the AWJ system. Özgünlük (Originality): Çalışmada, geleneksel veya bilgisayar kontrollü ahşap işleme makinelerine güçlü bir alternatif olarak yeni nesil ve çevre etkisi düşük aşındırıcı su jeti sistemi kullanılmıştır. / In the study, a new generation abrasive water jet system with low environmental impact was used as a powerful alternative to traditional or computer-controlled wood processing machines. Bulgular (Results): Levha kalınlığı ve ilerleme hızı artışı ile pürüzlülük değerleri artmıştır. Ayrıca, aşındırıcı miktarı ve kesici sıvı basıncı artışına bağlı olarak pürüzlülük özellikleri genel olarak azalma eğilimi göstermiştir. / Roughness values increased with increasing board thickness and feed rate. Additionally, roughness properties generally tended to decrease depending on the increase in the amount of abrasive and cutting liquid pressure. Sonuç (Conclusion): Örneklerin pürüzlülük değerlerinde levha kalınlığı ve ASJ ilerleme hızı parametreleri birinci derecede öneme sahiptir. / Board thickness and AWJ feed rate parameters are of primary importance in the roughness values of the samples.

Ormancılık Araştırma Dergisi

Bu çalışmada, farklı yöntemlerle ve farklı sıcaklık seviyelerinde ısıl işlemli ağaç malzeme yüzey... more Bu 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 bulunmuşt...

Maderas-Cienc Tecnol

The effect of thermal pretreatments on the dimensional change and humidity sensitivity of densifi... more The effect of thermal pretreatments on the dimensional change and humidity sensitivity of densified spruce (Picea orientalis) and poplar (Populus nigra) wood were investigated. A thermal pretreatment was applied on the wood specimens at 140 °C, 160 °C, 180 °C, and 200 °C for 7 h and 9 h. Wood specimens were then compressed at ratios of 20 % and 40 % at a temperature of 150 °C. The results showed that spring-back and thickness swelling increased in all specimens (thermally pre-treated and untreated) depending on the increase in compression ratio. However, set-recovery was determined higher at 20 % compression ratio. The equilibrium moisture content values ​​of untreated specimens and thermally pre-treated specimens at low temperatures (140 ºC and 160 ºC) were found lower than uncompressed specimens. The impact of compression ratio on equilibrium moisture content was not clear. Thermal pretreatments significantly affected the dimensional stability and hygroscopicity of densified speci...

BioResources

Beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) wood specimens were heat-treated separa... more Beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) wood specimens were heat-treated separately at three different temperatures (170 °C, 190 °C, and 210 °C) with steam treatment method (STM), oil treatment method (OTM), and hot-air treatment method (HTM). Then, the specimen surfaces were coated with water-based, polyurethane-based, and oil-based varnishes according to industrial applications. The study results show that both hardness and adhesion strength values of STM and HTM treated specimens were similar for both wood species. In contrast, these values were generally lower in OTM-treated specimens. For all applied methods, heat treatment temperature had no significant effect on hardness values. Varnish adhesion strength decreased in all heat-treated wood specimens compared to untreated specimens. Adhesion strength also decreased in STM- and HTM-treated specimens with increasing heat treatment temperature. Hardness values increased in all specimens coated with polyurethane- ...

BioResources

The effects of pre-impregnation on surface roughness, wettability, and morphological structure of... more The 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 °C, 150 °C, and 180 °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 ...

In this study, surface glossiness, roughness, hardness, color change, and varnish adhesion resist... more 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.

Bu çalışmada, su itici özellikteki maddeler ile muamele edilmiş farklı ahşap malzemelerin yoğunlu... more Bu çalışmada, su itici özellikteki maddeler ile muamele edilmiş farklı ahşap malzemelerin yoğunluk, su alma, boyutsal değişim ve retensiyon gibi bazı fiziksel özelliklerinin belirlenmesi amaçlanmıştır. Sarıçam (Pinus sylvestris L.), köknar (Abies bornmulleriana Mattf.), kayın (Fagus orientalis L.) ve meşe (Quercus petraea L.) odunlarından hazırlanan örnekler sıvı parafin, katı parafin, baz yağı ve vazelin ile 24 saat süresince emprenye edilmiştir. Örnekler daha sonra destile su içerisinde farklı sürelerde (2, 8, 24 ve 48 saat) bekletilmiştir. Araştırma sonuçlarına göre, en yüksek retensiyon değerleri katı parafin ile muamele edilen köknar örneklerinde elde edilmiştir. Uygulanan emprenye maddeleri, örneklerin (özellikle çam ve köknar) su alma oranı değerini önemli derecede düşürmüş ve ölçüsel stabilite direncini arttırmıştır. Su alma ve ölçüsel stabilite direnci testlerinde en iyi sonuçlar sırası ile katı parafin ve vazelin ile muamele edilmiş örneklerde bulunmuştur.

Coloration Technology, 2017

The aim of this study was to determine selected surface properties of varnished beech wood impreg... more The 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 (DL*, Da*, Db*, and DE*) in addition to scratch resistance and surface hardness values were calculated and evaluated. As a result of the weathering process, greater colour changes (DE*) 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-solutionimpregnated 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.

Mugla Journal of Science and Technology, 2016

Effect of thermo-mechanical densification and thermal post-treatment on the colour parameters (L*... more Effect of thermo-mechanical densification and thermal post-treatment on the colour parameters (L*, a*, b* and ΔE*) of beech (Fagus oriantalis L.) and pine (Pinus sylvestris L.) wood species were investigated. Wood specimens were densified at temperatures of 100 or 150 °C and compression ratios of 20% or 40%. Then, thermal post-treatment was applied to the specimens during 2 h at 190, 200, and 210 °C to provide dimensional stability in densified specimens. The colour change of the specimens was evaluated by CIEL*a*b* colour coordinate systems. The results showed that, the colour of the densified specimens at higher temperature and compression ratio was more changed. The compression temperature was more effective compared to compression ratio on the colour change of specimens. After the thermal post-treatment, colour characteristics of specimens have changed significantly depending on the increase in the treatment temperature, and specimens darkened. Densification processes has little effect on colour changes of the thermally post-treated specimens. The colour of pine specimens compared with the beech specimens more affected by the densification and thermal treatment applications. Morever, the change in a* value of specimens is more evident than the change in L* or b* values.

WOS: 000344184300068Effects of heat treatment on some physical properties of Scots pine (Pinus sy... more WOS: 000344184300068Effects 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. Whil...

Düzce Üniversitesi Bilim ve Teknoloji Dergisi, 2014

Çalışmada, Doğu kayını (Fagus orientalis L.) odununun bazı fiziksel özelliklerine termo-mekanik (... more Çalışmada, Doğu kayını (Fagus orientalis L.) odununun bazı fiziksel özelliklerine termo-mekanik (TM) yoğunlaştırma ve ısıl işlemin etkisi belirlenmiştir. Örnekler, özel tasarlanmış hidrolik preste 110 °C ve 150 °C sıcaklıkta, %20 ve %40 sıkıştırma seviyesinde radyal yönde sıkıştırılarak yoğunlaştırılmıştır. Daha sonra örneklere 190 °C, 200 °C ve 210 °C sıcaklıkta iki saat süre ile ısıl işlem uygulanmıştır. Fiziksel özelliklerde meydana gelen değişimleri tespit etmek için sıkıştırma oranı, geri esneme (spring-back) oranı, sıkıştırma kalınlığındaki geri dönüş oranı, sıkıştırma yönündeki (radyal) şişme ve yoğunluk testleri yapılmıştır. Araştırma sonuçlarına göre; aynı sıkıştırma seviyesinde (%20 veya %40), 110 ºC'de yoğunlaştırılan örneklerin geri esneme oranı düşük ve yoğunluk artışı daha yüksek elde edilmiştir. Sıkıştırma işlemleri ile yoğunlukta %35'e kadar artış sağlanırken, ısıl işlem sonrası yoğunlukta %5'e kadar azalma olmuştur. Isıl işlem sıcaklığı artışına bağlı ol...

Bioresources, 2020

The surface roughness of pine, beech, and oak wood cut in the abrasive water jet (AWJ) system was... more The surface roughness of pine, beech, and oak wood cut in the abrasive water jet (AWJ) system was evaluated for different processing parameters. Wood specimens were prepared in thicknesses of 18, 36, and 54 mm in both tangential and radial directions. Then the specimens were cut, applying three different feed speeds (50, 100, and 200 mm/min), three different abrasive flow rates (200, 300, and 450 g/min), and two different cutting liquid pressures (300 and 380 MPa) with the AWJ system. The Ra and Rz roughness values were higher in the tangential cut for pine and oak specimens and in the radial cut for beech wood. Roughness values increased in all specimens with increases in the AWJ feed speed and the wood thickness. In contrast, with increased amounts of abrasive, Ra and Rz values of the specimens decreased and surface smoothness tended to increase. Roughness values of pine and oak specimens generally decreased due to the increase in liquid pressure. However, an increase in the rough...

Drvna industrija, 2021

In this study, the effect of impregnation with natural extracts on decay resistance and color cha... more In 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 con...

The effects of different machining parameters on surface roughness values of thermally treated pi... more The effects of different machining parameters on surface roughness values of thermally treated pine, beech, and linden woods cut in a computer numerical control (CNC) router machine were examined. Wood specimens were thermally treated at 170, 190, and 210 °C for 2 h. Then, specimens were cut in the radial and tangential directions with three different spindle speeds (12000, 15000, and 18000 rpm) and three different feed rates (3000, 4000, and 6000 mm/min) using two different end mill tools (spiral and straight) on the CNC machine. The end mill type significantly affected the roughness values of the untreated and thermally treated specimens in both directions. Lower roughness values were found in the specimens (especially pine) machined with the straight end mill compared to those machined with the spiral end mill. Roughness generally decreased in the thermally treated specimens. However, thermal treatment temperature did not have a notable effect on roughness. As the spindle speed i...

The goal of this study was to determine the effect of densification and heat treatment on thermal... more The goal of this study was to determine the effect of densification and heat treatment on thermal conductivity properties of fir (Abies bornmulleriana Mattf.) wood. Fir wood specimens were densified with compression ratios of 25% and 50%, and at 100 °C or 140 °C. Then, the heat treatment was applied to the fir specimens at 185 oC and 212 oC for 2 hours according to ThermoWood® method. The study results showed that, densification and thermal treatment applications was effected thermal conductivity of the fir specimens. The thermal conductivity increased based on compression ratios and temperatures in the densified specimens. The thermal conductivity in the compressed specimens at high ratio (50%) was found higher than other specimens. After densification, additionally, thermal conductivity increasing on the radial surface was higher compared to the tangential surface. After heat treatment, thermal conductivity of the all specimens decreased significantly depending on the increase in ...

Holzforschung, 2020

In this study, the effect of thermo-mechanical densification on the density, hardness, compressio... more In this study, the effect of thermo-mechanical densification on the density, hardness, compression strength, bending strength (MOR), and modulus of elasticity (MOE) of fir and aspen wood pretreated with water repellents was analyzed. Wood specimens were impregnated with paraffin, linseed oil and styrene after pre-vacuum treatment. Then, the impregnated wood specimens were densified with compression ratios of 20 and 40%, and at 120, 150 and 180 °C. The results indicated that the density, hardness and strength properties of the all densified specimens (untreated and impregnated) increased depending on the compression ratio and temperature. For all tested properties, higher increases were obtained in the paraffin and styrene pretreated specimens compared to untreated samples. However, the increase rates in linseed oil pretreated specimens were generally lower than untreated specimens. Regarding water repellents the most successful results in all tested properties were determined in sty...

Drvna industrija, 2020

This study investigated the effect of pre-impregnation with water-repellent agents on the hygrosc... more This study investigated the effect of pre-impregnation with water-repellent agents on the hygroscopicity and dimensional stability of fir (Abies bornmulleriana Mattf.) and aspen (Populus tremula L.) woods. After pre-vacuum treatment, the samples were impregnated at atmospheric pressure with paraffin, linseed oil and styrene, and then densified at compression rates of 20 % and 40 % at 120, 150 and 180 °C. The results showed that water repellents significantly affected the hygroscopicity and dimensional stability of the densified wood samples. Compression recovery rate (CRR), thickness swelling (TS), equilibrium moisture content (EMC), and water absorption (WA) values of the densified samples decreased with impregnation pretreatments. The linseed oil treatment gave more positive CRR and TS results than paraffin. Lower EMC and WA values were found in the paraffin-treated samples. However, the most successful results for all tested properties were determined in the styrene pretreated sa...

Journal of Anatolian Environmental and Animal Sciences, 2019

In this study, the effects of epoxy and polyester resin applications on some mechanical strength ... more In this study, the effects of epoxy and polyester resin applications on some mechanical strength properties of scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa) wood samples were investigated. Firstly, in the circular sawing machine, a different numbers of channels (2+1 and 3+2) were opened on the surfaces of wood samples. Then, these channels were filled with casting type epoxy and polyester resins. The density, modulus of rupture (MOR), modulus of elasticity (MOE), and compression strength parallel to the grain (CS) tests were performed on the samples. According to the results of the study, the density values of pine and chestnut samples increased by 25% and 42%, respectively, depending on the number of channels after resin application. In addition, compared with epoxy resin applied samples, the density increase was higher in the polyester resin applied samples. After application of resins, a slight increase was observed in the MOR and MOE values of chestnut samples. However, CS values tend to decrease in these samples. In pine samples with resin applied, the strength properties (MOR, MOE and CS) decreased depending on the increase in the number of channels. Furthermore, the effect of the resin type on all strength properties of the samples was statistically insignificant.

Journal of Polytechnic, 2018

Bu çalışmada, nano-grafen (NG) ile modifiye edilmiş su bazlı vernik uygulanan kayın (Fagus orient... more Bu 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.

European Journal of Wood and Wood Products, 2017

The effects of thermo-mechanical densification and heat post-treatment on air-dry density, modulu... more The 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 Uludağ 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 °C. Then, the heat treatment was applied to the samples at 185 and 212 °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 °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.

Gazi Üniversitesi Fen Bilimleri dergisi, Nov 1, 2023

Bu çalışmada, aşındırıcı su jeti (ASJ) sisteminde kesilmiş orta yoğunluklu liflevha (MDF) malzeme... more Bu çalışmada, aşındırıcı su jeti (ASJ) sisteminde kesilmiş orta yoğunluklu liflevha (MDF) malzemenin kenar pürüzlülük özellikleri üzerine seçilmiş işleme parametrelerinin etkisi incelenmiştir. Örneklerde Ra, Rq ve Rz pürüzlülük değerleri analiz edilmiş ve endüstriyel uygulamalara yönelik öneriler sunulmuştur. / In this study, the effect of selected processing parameters on the edge roughness properties of medium density fiberboard (MDF) material cut in the abrasive water jet (AWJ) system was examined. Ra, Rq and Rz roughness values in the samples were analyzed and suggestions for industrial applications were presented. Şekil A: MDF örneklerin ASJ sisteminde kesilmesi ve pürüzlülük ölçümleri / Figure A:.Cutting of MDF samples in AWJ system and roughness measurements Önemli noktalar (Highlights) ➢ MDF örneklerin kesilmesinde yüksek verimliliğe sahip, düşük maliyetli, basit, temiz ve güvenilir bir teknoloji olan ASJ makinesi kullanılmıştır. / AWJ machine, which is a highefficiency, low-cost, simple, clean, and reliable technology, was used to cut the MDF samples. ➢ MDF örnekler ASJ makinesi ile farklı parametrelerde kesilmiş ve örneklerin pürüzlülük özellikleri belirlenmiştir. / MDF samples were cut with the ASJ machine at different parameters and the roughness properties of the samples were determined. ➢ Örneklerin kesim yüzeyi düzgünlüğünde seçilmiş işleme parametrelerinin etkisi önemli bulunmuştur. / The effect of selected processing parameters on the smoothness of the cutting surface of the samples was found to be significant. Amaç (Aim): Bu çalışmada, levha kalınlığı, kesici sıvı basıncı, aşındırıcı akış oranı ve ilerleme hızı faktörlerinin ASJ sisteminde kesilen MDF örneklerin pürüzlülük özelliklerine etkisinin belirlenmesi amaçlanmıştır. / In this study, it was aimed to determine the effects of board thickness, cutting liquid pressure, abrasive flow rate and feed rate factors on the roughness properties of MDF samples cut in the AWJ system. Özgünlük (Originality): Çalışmada, geleneksel veya bilgisayar kontrollü ahşap işleme makinelerine güçlü bir alternatif olarak yeni nesil ve çevre etkisi düşük aşındırıcı su jeti sistemi kullanılmıştır. / In the study, a new generation abrasive water jet system with low environmental impact was used as a powerful alternative to traditional or computer-controlled wood processing machines. Bulgular (Results): Levha kalınlığı ve ilerleme hızı artışı ile pürüzlülük değerleri artmıştır. Ayrıca, aşındırıcı miktarı ve kesici sıvı basıncı artışına bağlı olarak pürüzlülük özellikleri genel olarak azalma eğilimi göstermiştir. / Roughness values increased with increasing board thickness and feed rate. Additionally, roughness properties generally tended to decrease depending on the increase in the amount of abrasive and cutting liquid pressure. Sonuç (Conclusion): Örneklerin pürüzlülük değerlerinde levha kalınlığı ve ASJ ilerleme hızı parametreleri birinci derecede öneme sahiptir. / Board thickness and AWJ feed rate parameters are of primary importance in the roughness values of the samples.

Ormancılık Araştırma Dergisi

Bu çalışmada, farklı yöntemlerle ve farklı sıcaklık seviyelerinde ısıl işlemli ağaç malzeme yüzey... more Bu 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 bulunmuşt...

Maderas-Cienc Tecnol

The effect of thermal pretreatments on the dimensional change and humidity sensitivity of densifi... more The effect of thermal pretreatments on the dimensional change and humidity sensitivity of densified spruce (Picea orientalis) and poplar (Populus nigra) wood were investigated. A thermal pretreatment was applied on the wood specimens at 140 °C, 160 °C, 180 °C, and 200 °C for 7 h and 9 h. Wood specimens were then compressed at ratios of 20 % and 40 % at a temperature of 150 °C. The results showed that spring-back and thickness swelling increased in all specimens (thermally pre-treated and untreated) depending on the increase in compression ratio. However, set-recovery was determined higher at 20 % compression ratio. The equilibrium moisture content values ​​of untreated specimens and thermally pre-treated specimens at low temperatures (140 ºC and 160 ºC) were found lower than uncompressed specimens. The impact of compression ratio on equilibrium moisture content was not clear. Thermal pretreatments significantly affected the dimensional stability and hygroscopicity of densified speci...

BioResources

Beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) wood specimens were heat-treated separa... more Beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) wood specimens were heat-treated separately at three different temperatures (170 °C, 190 °C, and 210 °C) with steam treatment method (STM), oil treatment method (OTM), and hot-air treatment method (HTM). Then, the specimen surfaces were coated with water-based, polyurethane-based, and oil-based varnishes according to industrial applications. The study results show that both hardness and adhesion strength values of STM and HTM treated specimens were similar for both wood species. In contrast, these values were generally lower in OTM-treated specimens. For all applied methods, heat treatment temperature had no significant effect on hardness values. Varnish adhesion strength decreased in all heat-treated wood specimens compared to untreated specimens. Adhesion strength also decreased in STM- and HTM-treated specimens with increasing heat treatment temperature. Hardness values increased in all specimens coated with polyurethane- ...

BioResources

The effects of pre-impregnation on surface roughness, wettability, and morphological structure of... more The 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 °C, 150 °C, and 180 °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 ...

In this study, surface glossiness, roughness, hardness, color change, and varnish adhesion resist... more 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.

Bu çalışmada, su itici özellikteki maddeler ile muamele edilmiş farklı ahşap malzemelerin yoğunlu... more Bu çalışmada, su itici özellikteki maddeler ile muamele edilmiş farklı ahşap malzemelerin yoğunluk, su alma, boyutsal değişim ve retensiyon gibi bazı fiziksel özelliklerinin belirlenmesi amaçlanmıştır. Sarıçam (Pinus sylvestris L.), köknar (Abies bornmulleriana Mattf.), kayın (Fagus orientalis L.) ve meşe (Quercus petraea L.) odunlarından hazırlanan örnekler sıvı parafin, katı parafin, baz yağı ve vazelin ile 24 saat süresince emprenye edilmiştir. Örnekler daha sonra destile su içerisinde farklı sürelerde (2, 8, 24 ve 48 saat) bekletilmiştir. Araştırma sonuçlarına göre, en yüksek retensiyon değerleri katı parafin ile muamele edilen köknar örneklerinde elde edilmiştir. Uygulanan emprenye maddeleri, örneklerin (özellikle çam ve köknar) su alma oranı değerini önemli derecede düşürmüş ve ölçüsel stabilite direncini arttırmıştır. Su alma ve ölçüsel stabilite direnci testlerinde en iyi sonuçlar sırası ile katı parafin ve vazelin ile muamele edilmiş örneklerde bulunmuştur.

Coloration Technology, 2017

The aim of this study was to determine selected surface properties of varnished beech wood impreg... more The 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 (DL*, Da*, Db*, and DE*) in addition to scratch resistance and surface hardness values were calculated and evaluated. As a result of the weathering process, greater colour changes (DE*) 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-solutionimpregnated 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.

Mugla Journal of Science and Technology, 2016

Effect of thermo-mechanical densification and thermal post-treatment on the colour parameters (L*... more Effect of thermo-mechanical densification and thermal post-treatment on the colour parameters (L*, a*, b* and ΔE*) of beech (Fagus oriantalis L.) and pine (Pinus sylvestris L.) wood species were investigated. Wood specimens were densified at temperatures of 100 or 150 °C and compression ratios of 20% or 40%. Then, thermal post-treatment was applied to the specimens during 2 h at 190, 200, and 210 °C to provide dimensional stability in densified specimens. The colour change of the specimens was evaluated by CIEL*a*b* colour coordinate systems. The results showed that, the colour of the densified specimens at higher temperature and compression ratio was more changed. The compression temperature was more effective compared to compression ratio on the colour change of specimens. After the thermal post-treatment, colour characteristics of specimens have changed significantly depending on the increase in the treatment temperature, and specimens darkened. Densification processes has little effect on colour changes of the thermally post-treated specimens. The colour of pine specimens compared with the beech specimens more affected by the densification and thermal treatment applications. Morever, the change in a* value of specimens is more evident than the change in L* or b* values.

WOS: 000344184300068Effects of heat treatment on some physical properties of Scots pine (Pinus sy... more WOS: 000344184300068Effects 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. Whil...

Düzce Üniversitesi Bilim ve Teknoloji Dergisi, 2014

Çalışmada, Doğu kayını (Fagus orientalis L.) odununun bazı fiziksel özelliklerine termo-mekanik (... more Çalışmada, Doğu kayını (Fagus orientalis L.) odununun bazı fiziksel özelliklerine termo-mekanik (TM) yoğunlaştırma ve ısıl işlemin etkisi belirlenmiştir. Örnekler, özel tasarlanmış hidrolik preste 110 °C ve 150 °C sıcaklıkta, %20 ve %40 sıkıştırma seviyesinde radyal yönde sıkıştırılarak yoğunlaştırılmıştır. Daha sonra örneklere 190 °C, 200 °C ve 210 °C sıcaklıkta iki saat süre ile ısıl işlem uygulanmıştır. Fiziksel özelliklerde meydana gelen değişimleri tespit etmek için sıkıştırma oranı, geri esneme (spring-back) oranı, sıkıştırma kalınlığındaki geri dönüş oranı, sıkıştırma yönündeki (radyal) şişme ve yoğunluk testleri yapılmıştır. Araştırma sonuçlarına göre; aynı sıkıştırma seviyesinde (%20 veya %40), 110 ºC'de yoğunlaştırılan örneklerin geri esneme oranı düşük ve yoğunluk artışı daha yüksek elde edilmiştir. Sıkıştırma işlemleri ile yoğunlukta %35'e kadar artış sağlanırken, ısıl işlem sonrası yoğunlukta %5'e kadar azalma olmuştur. Isıl işlem sıcaklığı artışına bağlı ol...

Bioresources, 2020

The surface roughness of pine, beech, and oak wood cut in the abrasive water jet (AWJ) system was... more The surface roughness of pine, beech, and oak wood cut in the abrasive water jet (AWJ) system was evaluated for different processing parameters. Wood specimens were prepared in thicknesses of 18, 36, and 54 mm in both tangential and radial directions. Then the specimens were cut, applying three different feed speeds (50, 100, and 200 mm/min), three different abrasive flow rates (200, 300, and 450 g/min), and two different cutting liquid pressures (300 and 380 MPa) with the AWJ system. The Ra and Rz roughness values were higher in the tangential cut for pine and oak specimens and in the radial cut for beech wood. Roughness values increased in all specimens with increases in the AWJ feed speed and the wood thickness. In contrast, with increased amounts of abrasive, Ra and Rz values of the specimens decreased and surface smoothness tended to increase. Roughness values of pine and oak specimens generally decreased due to the increase in liquid pressure. However, an increase in the rough...

Drvna industrija, 2021

In this study, the effect of impregnation with natural extracts on decay resistance and color cha... more In 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 con...

The effects of different machining parameters on surface roughness values of thermally treated pi... more The effects of different machining parameters on surface roughness values of thermally treated pine, beech, and linden woods cut in a computer numerical control (CNC) router machine were examined. Wood specimens were thermally treated at 170, 190, and 210 °C for 2 h. Then, specimens were cut in the radial and tangential directions with three different spindle speeds (12000, 15000, and 18000 rpm) and three different feed rates (3000, 4000, and 6000 mm/min) using two different end mill tools (spiral and straight) on the CNC machine. The end mill type significantly affected the roughness values of the untreated and thermally treated specimens in both directions. Lower roughness values were found in the specimens (especially pine) machined with the straight end mill compared to those machined with the spiral end mill. Roughness generally decreased in the thermally treated specimens. However, thermal treatment temperature did not have a notable effect on roughness. As the spindle speed i...

The goal of this study was to determine the effect of densification and heat treatment on thermal... more The goal of this study was to determine the effect of densification and heat treatment on thermal conductivity properties of fir (Abies bornmulleriana Mattf.) wood. Fir wood specimens were densified with compression ratios of 25% and 50%, and at 100 °C or 140 °C. Then, the heat treatment was applied to the fir specimens at 185 oC and 212 oC for 2 hours according to ThermoWood® method. The study results showed that, densification and thermal treatment applications was effected thermal conductivity of the fir specimens. The thermal conductivity increased based on compression ratios and temperatures in the densified specimens. The thermal conductivity in the compressed specimens at high ratio (50%) was found higher than other specimens. After densification, additionally, thermal conductivity increasing on the radial surface was higher compared to the tangential surface. After heat treatment, thermal conductivity of the all specimens decreased significantly depending on the increase in ...

Holzforschung, 2020

In this study, the effect of thermo-mechanical densification on the density, hardness, compressio... more In this study, the effect of thermo-mechanical densification on the density, hardness, compression strength, bending strength (MOR), and modulus of elasticity (MOE) of fir and aspen wood pretreated with water repellents was analyzed. Wood specimens were impregnated with paraffin, linseed oil and styrene after pre-vacuum treatment. Then, the impregnated wood specimens were densified with compression ratios of 20 and 40%, and at 120, 150 and 180 °C. The results indicated that the density, hardness and strength properties of the all densified specimens (untreated and impregnated) increased depending on the compression ratio and temperature. For all tested properties, higher increases were obtained in the paraffin and styrene pretreated specimens compared to untreated samples. However, the increase rates in linseed oil pretreated specimens were generally lower than untreated specimens. Regarding water repellents the most successful results in all tested properties were determined in sty...

Drvna industrija, 2020

This study investigated the effect of pre-impregnation with water-repellent agents on the hygrosc... more This study investigated the effect of pre-impregnation with water-repellent agents on the hygroscopicity and dimensional stability of fir (Abies bornmulleriana Mattf.) and aspen (Populus tremula L.) woods. After pre-vacuum treatment, the samples were impregnated at atmospheric pressure with paraffin, linseed oil and styrene, and then densified at compression rates of 20 % and 40 % at 120, 150 and 180 °C. The results showed that water repellents significantly affected the hygroscopicity and dimensional stability of the densified wood samples. Compression recovery rate (CRR), thickness swelling (TS), equilibrium moisture content (EMC), and water absorption (WA) values of the densified samples decreased with impregnation pretreatments. The linseed oil treatment gave more positive CRR and TS results than paraffin. Lower EMC and WA values were found in the paraffin-treated samples. However, the most successful results for all tested properties were determined in the styrene pretreated sa...

Journal of Anatolian Environmental and Animal Sciences, 2019

In this study, the effects of epoxy and polyester resin applications on some mechanical strength ... more In this study, the effects of epoxy and polyester resin applications on some mechanical strength properties of scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa) wood samples were investigated. Firstly, in the circular sawing machine, a different numbers of channels (2+1 and 3+2) were opened on the surfaces of wood samples. Then, these channels were filled with casting type epoxy and polyester resins. The density, modulus of rupture (MOR), modulus of elasticity (MOE), and compression strength parallel to the grain (CS) tests were performed on the samples. According to the results of the study, the density values of pine and chestnut samples increased by 25% and 42%, respectively, depending on the number of channels after resin application. In addition, compared with epoxy resin applied samples, the density increase was higher in the polyester resin applied samples. After application of resins, a slight increase was observed in the MOR and MOE values of chestnut samples. However, CS values tend to decrease in these samples. In pine samples with resin applied, the strength properties (MOR, MOE and CS) decreased depending on the increase in the number of channels. Furthermore, the effect of the resin type on all strength properties of the samples was statistically insignificant.

Journal of Polytechnic, 2018

Bu çalışmada, nano-grafen (NG) ile modifiye edilmiş su bazlı vernik uygulanan kayın (Fagus orient... more Bu 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.

European Journal of Wood and Wood Products, 2017

The effects of thermo-mechanical densification and heat post-treatment on air-dry density, modulu... more The 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 Uludağ 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 °C. Then, the heat treatment was applied to the samples at 185 and 212 °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 °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.