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Analysis of forest product trade relationships between Turkey and European union member states
(2010) Akyüz, Kadri Cemil; Yıldırım, İbrahim; Balaban, Yasin; Korkut, Süleyman
The countries have needed to strengthen their trade relationships in the face of increasing competition conditions with globalization and a lot of unions emerged all over the world. The European Union, remaining in the foreground as an economical, commercial and political factor in these unions, possesses considerable influence, which a lot of countries want to be involved in. Turkey, being in the European integration process, looks for a place in European Union (EU) with its own resources and production power. Production and foreign trade data of the forest products industry, being among Turkey's important sectors, were compared with 25 different EU countries by using hierarchical cluster analysis, and Turkey's trade relationship was determined. The production amounts, import and export amounts and the values, between 2002 and 2006, belonging to the EU member countries and Turkey were used. It has been found that all countries could be divided into nine different groups according to countries' forest products industry structures. Competition advantage is experienced in the board sector but not in the paper and lumber sectors. The forest products industry sectors of Turkey have the capacity to compete with EU countries. © 2009 Academic Journals.
Bazı Yapraklı ve İbreli Ağaçlardan Üretilen Thermowood Panellerde Farklı Su Bazlı Vernik Katmanları Yüzey Özellikleri
(Düzce Üniversitesi, 2022) Aytin, Ayhan; Çakıcıer, Nevzat; Korkut, Süleyman
Bu çalışmada ThermoWood® yöntemi ile ısıl işlem uygulanan bazı ağaç türlerinde vernik katmanlarının koruyucu etkisi araştırılmıştır. Çalışmada, Türkiye’de doğal olarak yetişmekte olan, Titrek kavak (Populus tremula), Dişbudak (Fraxinus angustifolia), Doğu ladini (Picea orientalis) ve Uludağ göknarı (Abies bornmülleriana) ağaçları kullanılmıştır. Daha sonra ağaçlardan hazırlanan paneller ThermoWood® metodu ile ısıl işleme tabi tutulmuşlardır. Ardından panellere tek bileşenli (STB), çift bileşenli (SÇB) ve renkli (SRV) olmak üzere üç farklı su bazlı vernik (SBV) ilet yüzey işlemi uygulanmıştır. Vernikleme işlemi sonrası panellerde katman kalınlığı (ASTM D 6132), pandüllü sertlik (ASTM-D 4366), yüzeye yapışma direnci (Adhesion test apparatus 525-25) (ASTM D-4541), yüzey pürüzlülüğü (ISO 4287), ve parlaklık (ASTM-d 523) testleri yapılmıştır. Test sonuçlarına göre katman kalınlığı, pandüllü sertlik, yüzeye yapışma direnci, yüzey pürüzlülüğü ve parlaklık ölçümlerinde sırası ile olmak üzere en düşük ve en yüksek değerler 45.56, 55.41; 42.3,107; 2.63, 6.90; 0.859, 3.977; 4.76, 21.56 olarak belirlenmiştir.
Colour Changes of Heat-Treated Woods of Red-Bud Maple, European Hophornbeam and Oak
(Wiley-Blackwell, 2011) Şahin, Halil Turgut; Arslan, Mustafa Burak; Korkut, Süleyman; Şahin, Candan
Colour evolution and colour changes were analyzed from small specimens of three heat treated wood species using the CIE L*a*b* colour space. Upon heat exposure, the wood substance became darker of species; this was accompanied by a steady reduction in lightness. As treatment conditions (e.g., time and temperature) increase, various shades of yellow were favoured for the surface of red-bud maple wood (Delta b = 1.22-9.79). For European hophornbeam wood, increased times at elevated temperatures make a blue (-b) colour the better choice. The total colour difference (Delta E) of the surfaces of wood substrates appear to be well correlated with the treatment temperature and time. The FTIR spectra suggest that the level of modification was insufficient for removing the major cell wall constituents of the wood substrates. All heat-treated samples showed much less stability against colour difference in outdoor conditions. For red-bud maple, the greatest improvement was achieved for samples that were treated at 150 degrees C for 2 h (Delta E = 3.12). However, heat-treated oak wood had much less stability of colour difference for treatment conditions of 150 degrees C for 10 h. (C) 2010 Wiley Periodicals, Inc. Col Res Appl, 36, 462-466, 2011; Published online 7 October 2010 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/col.20634
Comparison of two drying schedules for European hophornbeam (Ostrya carpinifolia Scop.) lumber
(Taylor & Francis Inc, 2007) Korkut, Süleyman; Güller, Bilgin
Two types of conventional kiln-drying schedules (mild and harsh) based on moisture content (MC) were compared with regard to time, drying quality, and energy cost. The results were evaluated according to the classification of the European Drying Group. Proper drying periods of mild and harsh schedules were found to be 550 and 514h, respectively. Evaluations in terms of drying quality indicated that better results were achieved with the mild schedule, especially when comparing drying defects and final MC. From an energy efficiency point of view, the harsh schedule, by saving 36h of drying time, reduced electricity by 594KWh and was therefore found to be $65 more profitable in this trial.
COMPARISON OF TWO KILN-DRYING SCHEDULES FOR TURKISH HAZEL (Corylus colurna) LUMBER OF 5-CM THICKNESS
(Univ Bio-Bio, 2018) Korkut, Süleyman; As, Nusret; Büyüksarı, Ümit
Turkish hazel (Corylus colurna) lumber with a nominal thickness of 5 cm from the Kastamonu region, Turkey, was dried through conventional kiln drying using two different programs, a non-protective drying schedule and a protective drying schedule. The goal of the study was to obtain a kiln schedule that would maintain wood quality and also save drying time until a final moisture content of 8 +/- 2% was reached. The intensity of warping (twisting, bowing, cupping, crooking), superficial, internal, and end checks, residual stresses, drying rate, and moisture gradient of the dried woods were measured, and the results were evaluated according to the classification of the European Drying Group. The results showed a more homogeneous moisture profile, fewer occurrences of superficial checks, and an absence of internal checks when using the protective drying schedule due to low warping values compared with those for the non-protective drying schedule. From the point of view of energy efficiency, by saving 60 h of drying time, the non-protective schedule reduced electricity by 960 KWh and was therefore more profitable by $105,60 in this trial. Therefore, it seems that the protective drying schedule should be recommended as the optimum program for drying Turkish hazel lumber from the Kastamonu region at the commercial scale.
THE DENSITY, COMPRESSION STRENGTH AND SURFACE HARDNESS OF HEAT TREATED HORNBEAM (Carpinus betulus) WOOD
(Univ Bio-Bio, 2009) Gündüz, Gökhan; Korkut, Süleyman; Aydemir, Deniz; Bekar, İlter
The heat treatment of wood is an environment-friendly method for wood preservation. The heat treatment process only uses steam and heat, and no chemicals or agents are applied to the material during the process. Tests have shown no harmful emissions are apparent when working with the material. This process improves wood's resistance to decay and its dimensional stability. In this study, the density, compression strength and hardness of heat treated hornbeam (Carpinus hetzdus L.) wood were investigated. Wood specimens that had been conditioned at 65% rela degrees C for 4, 8, and 12 hrs. After heat treatment, compression strength and hardness were determined according to TS 2595 and TS 2479. The results showed that the decreases of compression strength and hardness were related to the extent of density loss. Both compression strength and hardness decreased with the increasing temperatures and durations of the heat treatment. While the maximum density loss observed was 16.12% at 210 degrees C and 12 hour, at these heat-treatment conditions, the compression strength approximately decreased 30% and hardness values in tangential, radial, and longitudinal directions approximately decreased by 55%, 54%, and 38%, respectively. Hence, it was concluded that there might be a relationship between changes of these wood properties.
Determination of bonding performance of several modified wood adhesives
(2011) Altınok, Mustafa; Atar, Musa; Keskin, Hakan; Korkut, Süleyman; Kocatürk, İlhan
We have assessed the effect on bonding performance of modifying synthetic wood adhesives. Wood samples were prepared from Scots pine (Pinus sylvestris L.) and oriental beech (Fagus orientalis L.). Samples were bonded using poly(vinyl acetate) (PVAc) and urea-formaldehyde (UF) adhesives modified with melamine-formaldehyde (MF) and phenol-formaldehyde (PF). Modified formulations included PVAc alone, PVAc + UF (at 15, 35 and 50% UF), UF alone, UF + MF (at 15, 35 and 50%), and UF + PF (at 15, 35 and 50% PF). Samples were exposed to three experimental environments: Standard atmosphere, cold water, and boiling water. For bonding strength determination, we used DIN 53 255 standard. We conclude that the adhesive modifications tested generally have no significant effect on bonding performance under standard atmospheric conditions, but do increase bonding performance under cold and boiling-water conditions. The best adhesive bonding strength was found using oriental beech samples with the UF + MF (50%) adhesive: 9.24 N/mm2 bonding strength under standard atmosphere conditions, 6.06 N/mm2 in cold water, and 4.39 N/mm2 in boiling water. © 2011 Academic Journals.
Drying schedules calculation of Camiyani Black Pine (Pinus nigra Arn. subsp pallasiana var. pallasiana) by computer programming
(Academic Journals, 2009) Aytekin, Alper; Gündüz, Gökhan; Kaygın, Bülent; Korkut, Süleyman; Onat, S. Murat
In this study, computer aided drying schedules were developed for Camiyani Black Pine (Pinus nigra var. pallasiana) lumber for less than 30 mm thick, between 30-60 mm thick and larger than 60 mm. Schedules were calculated on drying gradient basis. In this software (named KILNBRAIN), users can find more then one hundred other species' data (density, fiber saturation point, temperatures for warming up and drying periods, drying gradients for moisture contents above and less than 20%). Users can choose lumber thickness, initial and final moisture content, kiln type, air velocity and drying quality. One of the advantages of KILNBRAIN is that the drying schedule can be operated manually according to this data. Moreover, possible total drying duration can be predicted.
Drying schedules calculation of Camiyani Black Pine (Pinus nigra Arn. subsp. pallasiana var. pallasiana) by computer programming
(2009) Aytekin, Alper; Gündüz, Gökhan; Kaygın, Bülent; Korkut, Süleyman; Onat, Saadettin M.
In this study, computer aided drying schedules were developed for Camiyani Black Pine (Pinus nigra var. pallasiana) lumber for less than 30 mm thick, between 30-60 mm thick and larger than 60 mm. Schedules were calculated on drying gradient basis. In this software (named KILNBRAIN), users can find more then one hundred other species' data (density, fiber saturation point, temperatures for warming up and drying periods, drying gradients for moisture contents above and less than 20%). Users can choose lumber thickness, initial and final moisture content, kiln type, air velocity and drying quality. One of the advantages of KILNBRAIN is that the drying schedule can be operated manually according to this data. Moreover, possible total drying duration can be predicted. © 2009 Academic Journals.
The effect of air dried conditions on mechanical and physical properties of laminated and impregnated wood
(Academic Journals, 2009) Özalp, Murat; Korkut, Süleyman
In this study, laminated Scotch pine samples bonded with polyurethane adhesive were impregnated with water repellent (protim WR230) and preservative (tanalith-C). Non-impregnated and impregnated Scotch pine samples were air-dried by placing them uncovered in a concrete above ground for one year. Bending strength, compression strength, bonding strength and physical properties were determined. Bending strength was reduced by 20% for non-impregnated samples, 12% for tanalith impregnated samples, and 11.3% for protimWR230. Compression strength was increased by 5.5% for non-impregnated samples, 10.1% for tanalith treated and 10.4% for ProtimWR230. Bonding strength was reduced by 8.3% for untreated samples, but increased by 36.05 and 35.7% for tanalith and ProtimWR230, respectively. Impregnated samples were colonized by fungi during the one year outdoor conditioning; both dimensional and insect damages were not observed. Treated samples were well protected but nonimpregnated samples were covered by white rot, insects, color changes and considerable odour. In impregnating test samples, water and relative humidity affected the bonding properties positively for one year, and this increased the bonding and compression strength. But bending strengths were reduced. In determining the bonding and compression strengths, the applied force parallel to adhesive layer; while in determining bending strength the applied force is vertical to adhesive layer.
The effect of boiling time on the surface roughness of rotary-cut veneers from oriental beech (Fagus orientalis L.)
(Elsevier Science Sa, 2008) Dündar, Türker; As, Nusret; Korkut, Süleyman; Ünsal, Öner
The objective of this study was to investigate effects of boiling time on surface roughness of beech (Fagus orientalis L.) veneer manufactured using the rotary cutting method. Three logs of oriental beech were subjected to softening process by boiling them in water (60-70 degrees C) for various times (e.g. 20,40, and 60 h) and they were peeled immediately. For surface roughness, veneer samples were taken from outer, center, and inner (near to pit) parts of logs and the distance of the locations where the samples were taken from the pith were the same. Veneer specimens have a dimension of 10 cm (width) by 20 cm (length) by 0.14 cm (thickness). Three roughness parameters, average roughness (R-a), mean peak-to-valley height (R-z), and maximum roughness (R.) for each group were measured according to DIN standard 4768 by using stylus profilometer and compared with one another. Except the boiling time, other factors (species, knife angle, peeling angel, etc.) were kept the same. The results show that, the surface of veneers, taken from heartwood and center of the logs boiled 60 h were significantly rougher than 20 and 40 h. But peeling veneers obtained from sapwood of logs boiled 20 h displayed significantly rougher surface than 40 and 60 h. For all samples, applying 40-h boiling period can minimize the roughness value. Therefore, it seems that 40-h boiling period is suitable in order to minimize the surface roughness of rotary-cut veneers manufactured from all of beech (F. orientalis L.) logs parts (inner, center, and outer) (C) 2007 Elsevier B.V. All rights reserved.
Effect of Heat Treatment of Wild Cherry Wood on Abrasion Resistance and Withdrawal Capacity of Screws
(Zagreb Univ, Fac Forestry, 2015) Aytin, Ayhan; Korkut, Süleyman; As, Nusret; Ünsal, Öner; Gündüz, Gökhan
In its wise use, many properties of wood are important. Among these properties, wood abrasion resistance (AR) and withdrawal capacity of screws (WCS) are deemed to be relatively significant. It is well know that heat treatment changes the resistance features of wooden materials by changing the structural characteristics of wood. Within the scope of this study, the effects were investigated of the temperature and duration of heat treatment of Wild Cherry (Cerasus avium (L.) Monench) on its AR and its WCS in the radial direction and tangential direction. The test results indicated that weight loss (WL) and thickness reduction (TR) remained almost the same in the radial direction specimen, but there was significant TR in the tangential direction specimen. As a result of these changes, the abrasion effect of the S-42 abrader diminished based on the increase in the number of cycles. However, in both the radial and tangential direction, the WCS decreased to a significantly greater extent in the heat-treated specimens than in the control specimens.
Effect of heat treatment on mechanical properties of hazelnut wood (Corylus columa L.)
(Elsevier Sci Ltd, 2009) Korkut, Süleyman; Hızıroğlu, Salim
Heat treatment is widely used to improve the dimensional stability of wood and wood products. The objective of this study was to evaluate effects of heat treatment on mechanical properties of hazelnut wood (Corylus columa L). Samples were exposed to temperature levels of 120 degrees C, 150 degrees C, and 180 degrees C for time spans ranging from 2 to 10 h Mechanical properties including compression strength, modulus of elasticity, modulus of rupture, janka-hardness, impact bending strength, tension strength perpendicular to grain, tension strength parallel to grain, shear strength, and cleavage strength of heat-treated samples were determined. Maximum reduction values of 68.11%, 64.97%, and 58.75% were found for Janka-hardness in radial, tangential, and tension strength parallel to grain for the samples exposed to 180 degrees C for 10 h, respectively. Overall results showed that treated samples had lower mechanical properties than those of the control samples. Statistically significant difference was determined (p=0.05) between mechanical properties of the control samples and those of treated at 180 degrees C for 10 h. (C) 2008 Elsevier Ltd. All rights reserved.
The Effect of Heat Treatment on Some Mechanical Properties and Color Changes of Uludag Fir Wood
(Taylor & Francis Inc, 2010) Gündüz, Gökhan; Aydemir, Deniz; Korkut, Süleyman
In this study, the effects of heat treatment on color, mass loss, compression strength, and hardness of Uludag fir (Abies bornmulleriana Mattf.) were investigated. Wood specimens conditioned at a relative humidity of 65% and a temperature of 20 degrees C were subjected to heat treatment at 170, 190, and 210 degrees C for 4, 8, and 12h. After heat treatment, compression strength and hardness were determined according to TS 2595 and TS 2479. Color changes were determined according to DIN5033. The results showed that compression strength and hardness of Uludag fir wood decreased to varying extents in relation to intensity of treatment, whereas mass loss increased. We determined that treatment temperature had a more significant effect on color changes than did treatment time. The color of the wood became darker at the higher treatment temperatures.
Effect of heat treatment on some mechanical properties of laminated window profiles manufactured using two types of adhesives
(Mdpi, 2008) Korkut, Derya Sevim; Korkut, Süleyman; Dilik, Tuncer
The mechanical properties of laminated window profiles manufactured using two types of adhesives were determined. The objective of this study is to evaluate the effects of heat treatment on some mechanical properties of laminated window profiles that manufactured from Kosipo (Entandrophragma candollei Harms.) using differenet type adhesives. Commercially produced polyurethane based Macroplast UR 7221 and polyvinyl acetate (PVAc) adhesive were used for experiments. The overall test results were found to be comparable to those obtained in the previous studies. Both types of adhesives resulted in significant differences in their strength characteristics at 95% confidence level. Adhesive UR 7221 improved the overall properties of the samples in contrast to PVAc.
Effect of High-Temperature Treatment on the Mechanical Properties of Rowan (Sorbus aucuparia L.) Wood
(Taylor & Francis Inc, 2009) Korkut, Süleyman; Budakçı, Mehmet
Heat treatment is a wood modification method that has been used to some extent in improving timber quality. The high temperature thermal treatment of wood is an environmentally friendly method for wood preservation. This technique has attracted considerable attention both in Europe and in North America in recent years. This article presents the results of experimental studies on influence of heat treatment on the mechanical properties of Rowan (Sorbus aucuparia L.) wood performed in order to understand its role in wood processing. Samples were exposed to temperature levels of 120, 150, and 180 degrees C for time spans ranging from 2 to 10h. Mechanical properties including compression strength, modulus of elasticity, modulus of rupture, Janka hardness, impact bending strength, tension strength perpendicular to grain, tension strength parallel to grain, shear strength, and cleavage strength of heat-treated samples were determined. Maximum reduction values of 34.12, 28.40, and 26.37% were found for impact bending strength, tension strength parallel to grain, and cleavage strength for the samples exposed to 180 degrees C for 10h, respectively. Overall, the results showed that treated samples had lower mechanical properties than those of the control samples. Statistically significant difference was determined (P=0.05) between mechanical properties of the control samples and those treated at 180 degrees C for 10h.
The effect of open air conditions on the properties of wooden material
(Academic Journals, 2009) Özalp, Murat; Ordu, Mustafa; Korkut, Süleyman
In this study, the impregnation materials of Tanalith-C (CCA) and Protim 230 WR were used as preservative and water repellant. Wooden materials were taken from beech and black pine. The samples were made subject to weathering conditions for one year. At the end of this period, changes occurred in the samples' bending strength, compression strength and physical properties were examined. As a result of this study, it was observed that no significant variations occurred in mechanical values of the impregnated samples; however, severe losses occurred in case of the non-impregnated samples. It was seen that impregnation type provides different protection according to the type of the wooden material. It was observed that discoloration is more significant in the non-impregnated samples compared with those impregnated. Both of the impregnation materials provide sufficient protection.
Effect of Pretreatment of Raw Material on Properties of Particleboard Panels Made from Wheat Straw
(North Carolina State Univ Dept Wood & Paper Sci, 2013) Bekhta, Pavlo; Korkut, Süleyman; Hızıroğlu, Salim
The objective of this study was to evaluate properties of experimental particleboard panels manufactured from wheat straw that had been pretreated with acetic anhydride, soapy solution, hot water, or steam. Wheat straw particles were mixed with commercially manufactured wood particles at a ratio of 60%. Control straw particleboards with non-treated straw and wood particles were also produced. The results showed that the pretreatment of wheat straw significantly improved both the physical and mechanical properties of the straw particleboards. Panels made from wheat straw treated with a 9% solution of acetic anhydride or boiled in a soapy solution resulted in the highest mechanical properties, with an increase in bending strength values. Regarding internal bond strength, the samples made from wheat straw particles treated with acetic anhydride and a soapy solution had 2 and 3 times higher values, respectively, than those of non-treated samples. It seems that the pretreatment of wheat straw had a greater effect on the thickness swelling of the specimens than on their water absorption.
The effect of protective dye layer applied with different thicknesses on the paper coated blockboard to the roughness and color characteristics
(Academic Journals, 2010) Çakıcıer, Nevzat; Erdinler, Seda; Ulay, Göksel; Korkut, Süleyman
This study is carried out for determining the changes occurring on the amount of the material used on the protective layer when polyurethane and acrylic (lacquered) dye is applied on the test samples prepared from sandwich type composite (blockboard) boards with their surface coated or uncoated with paper, which are used for the yacht furniture and interior decoration. After applying polyurethane and acrylic dye on the 10 test samples prepared as coated or uncoated with paper with 10 x 10 x 1.6 cm sizes from blockboard, the average surface roughness (Ra) values of the protective layer as applied in TS 6956 (2004) have been determined and the total color differences have been determined according to the essentials specified in ASTM-D2244-07e1. According to the result of the study, concealing dyeing is obtained with less roughness and no color difference by using less lacquer dye on the boards coated with paper. With this study, it is possible to suggest that coating with paper before lacquer dyeing can be a preferable application in terms of cost and time saving.
The effect of sea water on laminated wooden material
(Academic Journals, 2009) Özalp, Murat; Perçin, Osman; Korkut, Süleyman
In the present study, black pine samples laminated with epoxy and polyurethane glues were treated with various wood preservative chemicals and made subject to seawater for one year. The samples were examined from the point of view of physical features such as changes in odor and color as well as their mechanical values in 3-month periods. For this purpose, the samples were made subject to bending tests perpendicular to the fibers, compression tests parallel to the fibers and adhesion tests. As a result of this study, it was observed that, non-impregnated samples were excessively decayed and they were so decomposed and destroyed that they could not be used anymore within the first 6 months. It was determined that, sea insects nested on the said samples and began to live there, sea worms destroyed the wooden surfaces by drilling them, the said surfaces were covered with seaweed, the surfaces became extremely soft and there were white decays on some regions. In case of impregnated samples, very small changes occurred in odor and color and moreover, any decay was not seen. Also, significant changes were observed as a result of mechanical tests.

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