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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 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 Effect of Thermo-Vibro-Mechanic (R) Densification Process on the Gloss and Hardness Values of Some Wood Materials(North Carolina State Univ Dept Wood & Paper Sci, 2019) Şenol, Süleyman; Budakçı, MehmetThis study aimed to determine the gloss and hardness values of low-density wood materials densified using the Thermo-Vibro-Mechanic (R) (TVM) method after pretreatment with wood stain and wood preservative. This was carried out with a TVM density press that was designed and produced with the support of project 115O138 of the Scientific and Technological Research Council of Turkey (TUBITAK). The samples obtained from Uludag . fir (Abies bornmuelleriana Mattf.) and black poplar (Populus nigra L.) were pretreated with wood stain and wood preservative prior to the TVM densification process. The TVM densification operation was conducted at three different temperatures, three different vibration pressures, and three different vibration times. After the TVM densification process, changes in the gloss (ISO 2813 2014) and Brinell hardness values (TS 2479 1976) of the samples were determined. According to the results, the TVM densification method increased the gloss value of the Uludag fir and black poplar wood pretreated with the wood preservative by 175% and 1390%, respectively, and increased the Brinell hardness value by 63% and 150%, respectively.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 Effect of Thermal Ageing on the Gloss and the Adhesion Strength of the Wood Varnish Layers(North Carolina State Univ Dept Wood & Paper Sci, 2013) Demirci, Zafer; Sönmez, Abdullah; Budakçı, MehmetThe present study investigated the effect of thermal ageing of several wood varnishes on film characteristics. For this purpose, alkyd, two-part polyurethane (urethane-alkyd), and water-borne (self-cross-linked polyurethane) varnishes were applied on Scots pine (Pinus sylvestris L.), Eastern beech (Fagus orientalis L.), and sessile oak (Quercus petraea L.). The test samples had 8% or 12% moisture content. The samples were then thermally aged for 25, 50, 75, and 100 days at 25, 50, 75, and 100 degrees C. The decrease in adhesion strength of the varnish layers and the loss in surface gloss were determined in accordance with the ISO 4624 and ISO 2813 standards. The results of the study indicated that thermal ageing caused a decrease in the adhesion strength and gloss values.Öğe Effect of Resin Cleaning Process on Adhesion Strength of Water-Based Varnishes(North Carolina State Univ Dept Wood & Paper Sci, 2019) Budakçı, Mehmet; Saygın, Emre; Şenol, SüleymanThe purpose of this study was to determine how resin, a side compound of wood, and resin cleaning methods affect the adhesion strength of water-based varnishes. For this purpose, scots pine (Pin us sylvestris L.), black pine (Pinus nigra subsp.), larch (Larix decidua Mill.), and spruce (Picea abies (L.) H. Karst.), woods with different amounts of resin in their anatomical structure were examined. Physical and chemical resin cleaning procedures were applied to the samples using acetone, cellulosic (lacquer) thinner, sodium hydroxide (NaOH), sodium hydroxide + hydrogen peroxide (NaOH + H2O2), and soft soap chemicals. Later, single-component and double-component water-based varnishes were applied to these sample surfaces. The samples were then subjected to a hot and cold-check test in accordance with the principles set forth in ASTM D 1211 (1997). In the examples, the changes in adhesion strength were examined according to TS EN ISO 4624. According to the results, resin cleaning chemicals and methods reduce the adhesion strength of water-based varnishes.Öğe Effect of Bleaching on Hardness, Gloss, and Color Change of Weathered Woods(North Carolina State Univ Dept Wood & Paper Sci, 2014) Budakçı, Mehmet; Karamanoğlu, MehmetThe aim of this study was to eliminate the problems of hardness, gloss, and color change of some wood materials exposed to weathering conditions using a bleaching procedure to attempt to return the wood material to its natural state. For this, wood samples of Scots pine (Pinus sylvestris L.), Eastern beech (Fagus orientalis L.), sessile oak (Quercus petraea L.), and chestnut (Castanea sativa Mill.) were exposed to weathering conditions based on 12 months ASTM D-1641, followed by a bleaching procedure using 18% solutions of S1 (NaOH + H2O2), S2 (NaOH + Ca(OH)(2)), S3 (KMnO4 + NaHSO3 + H2O2), S4 (NaSiO3 + H2O2), and the commercial product S5 (Cuprinol Decking Restorer-(H2C2O4 + C2H4(OH)(2)). The color, gloss, and hardness changes of samples were determined according to ASTM D 2244-2, EN ISO 2813, and ASTM D 2240 standards. As a result, hardness and gloss values of all woods decreased due to weathering conditions and the wood color turned grey due to degradation. When comparing the weathered samples to the bleached samples, the hardness value was found to be highest in pine wood bleached with the S2 solution, and the gloss value was highest in oak wood bleached with the S1 solution. The greatest color change was found in pine, beech, and chestnut samples bleached with the S4 solution and in oak samples bleached with the S1 solution.Öğe Determination of the Surface Roughness of Heat-Treated Wood Materials Planed by the Cutters of a Horizontal Milling Machine(North Carolina State Univ Dept Wood & Paper Sci, 2013) Budakçı, Mehmet; İlçe, Abdullah Cemil; Gürleyen, Tuğba; Utar, MustafaThe aim of the present study was to determine the surface roughness of heat-treated Scots pine (Pinus sylvestris L.), Eastern beech (Fagus orientalis L.), Uludag fir (Abies bornmulleriana Mattf.), and sessile oak (Quercus petraea L.) wood material samples following planing by the cutters of a horizontal milling machine. The samples that were heat-treated at 140 degrees C or 160 degrees C for 3, 5, or 7 hours were then processed by star blades or razor blades, which are the most frequently used blade types in a milling machine. The surface roughness of the samples was determined by a touch (spined) scan device (TIME TR200), as indicated by the ISO 4287 principle. The results of the study indicate that heat treatment decreases the surface roughness value of the wood material and a significant difference in surface roughness cannot be detected between planing using the razor blade or the star blade.Öğe Determination of machinery and knife strains in the planing of wood-based panels(Springer Japan Kk, 2015) Gürleyen, Levent; Budakçı, MehmetIn this study, strains that are caused by wood-based panels on horizontal milling machines and other cutting devices were examined. In order to fulfill this aim, samples of wood-based panels such as particleboard, medium density fiberboard (MDF), blockboard, okoume (Aucoumea klaineana) plywood, poplar (Populus x euramericana) plywood, and oriented strand board (OSB) were examined. The strains that milling machines and planer head with reversible knives suffered were measured by an amperemeter using an experimental mechanism with six different wood-based panels, three different engine revolution speeds (rev/min), and three drive forward speeds (m/min). Using the experimental data and the data derived from wood-based panels, engine revolution speed, and drive forward speed, several regression equations were developed in order to anticipate probable strains for each of the wood-based panels. As a consequence, the utmost strains observed on machinery during planing were caused by okoume plywood, followed by MDF, OSB, particleboard, blockboard, and poplar plywood in decreasing order of intensity. It was also observed that the spent current values (A) increased during planing in which engine revolution speed and drive forward speed are always kept high. It was also clearly seen that the wood-based panels were more resistant to the machinery and the knives when they were operated at higher speeds. The results of experiments correlated well with the predicted values produced by the anticipation regression models (R-2 = 0.898-0.965).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 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 The Effect of Fiberboard Modification on Adhesion Strength to Polyvinyl Chloride (PVC) Sheets or Eastern Beech (Fagus orientalis L.) Veneers(North Carolina State Univ Dept Wood & Paper Sci, 2018) Kara, Adem; Budakçı, Mehmet; Çamlıbel, OsmanThe adhesion strength was evaluated for polyvinyl chloride (PVC) and Eastern beech (Fagus orientalis L.) veneers glued onto specially produced fiberboards using urea-formaldehyde (UF), polyvinyl acetate (PVAc), and polyurethane (PU) adhesives. Inorganic fillers including rock salt (NaCI), calcite (CaCO3), borax pentahydrate (Na(2)B(4)4O(7)center dot 5H(2)O), or talc (3MgO center dot 4SiO(2)center dot H2O) were incorporated into the fiberboards at levels of 3%, 6%, and 9%. The adhesion strength of the samples was determined in accordance to Turkish Standard TS EN 311 (2005). Scanning electron microscopy (SEM) was employed to determine the structural morphology at the bonding interface of the veneers and the modified fiberboards. The results of this study indicated that veneer adhesion strength was reduced by the addition of inorganic fillers to the fiberboard. The highest adhesion strength was obtained with Eastern beech veneer that was glued using UF adhesive on the control samples without inorganic fillers. It was concluded that UF and PVAc adhesives are not suitable for bonding PVC veneers onto fiberboard surfaces.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 Surface roughness and brightness of scots pine (Pinus sylvestris) applied with water-based varnish after densification and heat treatment(Springer Japan Kk, 2015) Pelit, Hüseyin; Budakçı, Mehmet; Sönmez, Abdullah; Burdurlu, ErolThis research was aimed at determining the surface roughness and surface brightness properties of Scots pine (Pinus sylvestris L.) wood samples to which water-based varnishes were applied after thermo-mechanical densification and heat treatment. Samples; after densifying by compression in the radial direction at two different rates (20 and 40 %) and two different temperatures (110 and 150 A degrees C), samples were subjected to 2 h of heat treatment at 190, 200, and 210 A degrees C. Then, surface of the samples was varnished with one-component (OCW) and two-component (TCW) water-based varnishes. The changes occurring in surface roughness and surface brightness of the samples were determined according to the basis of TS 2495 EN ISO 3274, TS 6212 EN ISO 4288 and TS EN ISO 2813. According to results of the research, surface roughness decreased and surface brightness increased in densified samples. On the other hand, an increase in the heat treatment temperature led to an increase in surface roughness and a decrease in surface brightness. Also, regarding the effect of varnish type on both surface roughness and surface brightness, better results were obtained in the surface OCW applied compared to those TCW applied.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 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 Application of Electrostatic Powder Coating on Wood Composite Panels Using a Cooling Method. Part 1: Investigation of Water Intake, Abrasion, Scratch Resistance, and Adhesion Strength(North Carolina State Univ Dept Wood & Paper Sci, 2019) Akkuş, Memiş; Akbulut, Turgay; Candan, ZekiPowder coating is environmentally friendly and safe in terms of human health and is used especially on home appliances and in the automotive sector. Because of these advantages, recent studies have expanded work on the application of powder coating on non-conductive surfaces. Within the scope of this research, low temperature curing (120 degrees C to 130 degrees C) was applied on wood-based composite panels of medium-density fiberboard (MDF), particleboard, and plywood to facilitate conductivity. Epoxy, polyester, and hybrid (epoxy-polyester) types of powder paint and water-based liquid paint (control group) were applied to the surface of materials. Panels coated with the powder coatings were compared to the panels coated with the water-soluble acrylic resin coating. The prepared samples were analyzed for performance properties. The best results for thickness swelling, water absorption, adhesive strength, abrasion, and scratch resistance were found for the plywood coated with water-based liquid paint, MDF coated with polyester-based powder paint, plywood coated with hybrid powder paint, particleboard coated with hybrid powder paint, and plywood coated with epoxy powder paint, respectively.Öğe Analysis of Usability in Furniture Production of Wood Plastic Laminated Board(North Carolina State Univ Dept Wood & Paper Sci, 2015) İlçe, Abdullah Cemil; Budakçı, Mehmet; Özdemir, Serkan; Akkuş, MemişThe objective of this study was to manufacture a lightweight and easily producible wood plastic laminate (WPL) board that could be used in the furniture sector. Eastern beech (Fagus orientalis L.) veneer papels (A) and hollow polycarbonate boards (B), both with a thickness of 4 mm, were laminated in different combinations using polyurethane (PUR) and polychloroprene (PCR) adhesives. The physical and mechanical properties of the WPL boards obtained were determined according to the principles specified in the EN 326-1, EN 317, EN 310, ASTM D1037, and ASTM D1761 standards. Subsequently, the specimens were compared with particle boards (PB), medium density fiberboards (MDF), and okoume plywoods (PW). According to the results, the AABAA, ABABA, and ABBBA combinations of the WPL materials had better physical properties, such as weight, water absorption, and swelling thickness, compared to the other composites. Furthermore, because the WPL materials had a high bending resistance, modulus of elasticity, and nail and screw withdrawal strength, they could be used instead of PB and MDF. The WPL material obtained within the scope of this study are suitable for furniture making.Öğe Adhesion properties of some protective layers exposed to outside weather conditions for five years(Tubitak Scientific & Technical Research Council Turkey, 2013) Budakçı, Mehmet; Taşçıoğlu, CihatIn this study, the long-term (5-year) performances of 2 varnish systems, semitransparent alkyd-based brown stain (SABBS) and alkyd-based clear varnish (ABCV), were evaluated on preservative-treated Scots pine (Pinus sylvestris L.) sapwood. Prior to varnish application, specimens were impregnated with 2 different types of wood preservative. The experimental variables were varnish type, layer thickness, and wood preservative. ASTM D 1641 was followed for exposing wood specimens to outdoor conditions. The effects of long-term exposure on adhesion properties of applied varnish systems were tested according to ASTM D 4541. Long-term outdoor exposure resulted in 4.2% and 33.9% reductions in the adhesion properties of SABBS and ABCV varnish systems, respectively. The layer thickness and preservative type did not show any statistical reductions in adhesion properties.
