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Öğe Analysis of Postural Load During Tasks in Some Machines Related to Panel Furniture Production By Using The OVAKO Working Posture Analyzing System (OWAS)(Kastamonu Univ, Orman Fak, 2012) Ulker, Onur; Burdurlu, ErolIn this study, it was aimed to classify and analyze the posture of body members of workers working at the machines of circular saw, edge banding and vertical boring at the partial process of panel furniture manufacturing according to the loads and strains. Research was realized at a small-scale firm in Ankara. OWAS (Ovako Working Postures Analyzing System) method was used in classifying of working postures. In accordance with the method, processes were taken video cam in 30 seconds and postures of the body members of workers were classified according to the danger. It was made modifications in the processes that higher loadings and strains taken place and new processes were taken video cam again for classification and analyzing. The arrangements that were made provided a reduction 37 % in the values of danger class.Öğe Effect of Densification Temperature and Some Surfacing Techniques on the Surface Roughness of Densified Scots Pine (Pinus sylvestris L.)(North Carolina State Univ Dept Wood & Paper Sci, 2014) İmirzi, Hasan Özgür; Ülker, Onur; Burdurlu, ErolThe effects of densification temperature, planing, circular sawing, and sanding on the surface roughness of densified Scots pine using the open-system thermodynamic method were studied. Densification was applied to Scots pine at 6 MPa pressure and at temperatures of 120 degrees C, 140 degrees C, and 160 degrees C. A total of 1040 specimens (160 x 50 x 10 mm) were prepared using the surfacing techniques of planing, circular sawing, and sanding. The surface roughness of the specimens were measured in conformance with the TS 2495, EN ISO 3274, and the TS 6212 EN ISO 4288 standards, and the results were subjected to statistical analysis. The surface roughness of the planed surfaces was 26% lower, of the surfaces cut circularly was 38% lower, and of the sanded surfaces was 32% lower in densified Scots pine compared to undensified Scots pine. According to the densification temperature, while the lowest roughness was obtained in the densified specimens at 140 degrees C, raising the temperature to 160 degrees C increased the roughness. An increase in the number of blades in planing, the tooth number in circular sawing, and the grit number in planing decreased the surface roughness. Furthermore, the roughness was less in tangential surfaces compared to radial surfaces.Öğe The Effect of Densification Temperature on Some Physical and Mechanical Properties of Scots Pine (Pinus sylvestris L.)(North Carolina State Univ Dept Wood & Paper Sci, 2012) Ulker, Onur; Imirzi, Ozgur; Burdurlu, ErolAs wood's density increases, strength properties tend to increase due to a decrease in cavity volume. This study aimed to determine the effect of temperature levels in the densification process with an open-system thermomechanical method on the density, bending, modulus of elasticity in bending, compression, shear strength, and Brinell hardness in radial/tangential directions of Scots pine. The densification process significantly increased the strength properties of Scots pine. This increase stemmed from the decrease in the rate of cavities with the densification process, which also resulted in an increase in cell wall elements that have load-bearing properties per unit volume. An increase in densification temperature decreased strength properties. The decrease in the strength values can be explained by increasing chemical degradation with a rise in the temperature level. The most suitable temperature level was 120 degrees C for a higher bending, shear, and compression strength, and it was 140 degrees C for a higher radial and tangential hardness in the densification of Scots pine. Increases of 42% in the bending strength, 20% in the shear strength, 47% in the compression strength, 242% in the radial hardness, and 268% in the tangential hardness were obtained after densification.Öğe Effect of Glass Wool and Stone Wool Additives on Some Mechanical Properties of Wood Composites(North Carolina State Univ Dept Wood & Paper Sci, 2016) Ulker, Onur; Burdurlu, ErolMechanical properties of wood composites made from multiple wood species (50% Crimean pine, 30% Eastern Black Sea oak, 15% quaking aspen, and 5% wood machining residues) were evaluated using various amount of glass wool (GW) and stone wool (SW) additives. A total of 70 experimental panels were produced with a target density of 640 kg/m(3). The bending strength, modulus of elasticity, tensile strength parallel to the surface of boards, tensile strength perpendicular to the surface of boards (internal bond), and cutting (shear) strength parallel to the surface of boards were determined. After statistical analysis, the results indicated that the SW and GW additives decreased the bending strength and modulus of elasticity by 49% in almost all boards. The addition of SW resulted in a 6% reduction in the tensile strength parallel to the surface. Relative to SW, GW resulted in an additional 8% reduction in shear strength, a 3% reduction in the screw tensile strength perpendicular to the surface, and a 6% reduction in the tensile strength parallel to the surface. Thus, the SW and GW additives decreased all the selected mechanical properties of wood composites.Öğe Effects of Some Mineral Wools and Adhesives on Burning Characteristics of Particleboard(North Carolina State Univ Dept Wood & Paper Sci, 2015) Ulker, Onur; Burdurlu, ErolIn this study, effects of adhesive and additive's type and ratio on burning characteristics of particleboard (PB) added glass wool (GW) and rock wool (RW) were researched. PB's furnish was derived from 50% Crimean pine, 30% Eastern Black Sea oak, 15% quaking aspen, and 5% residues of wood machining, and moisture content of furnish was 1.5 to 3%. Seventy PBs with 0.64 g/cm(3) density, urea formaldehyde (UF)/melamine formaldehyde (MF) fixed amount, 14 mm thickness, 45x45 cm(2) dimensions and 10%, 15%, 20% SW/GW additives were produced. The 150 degrees C pressing temperature with 25 kg/cm(2) compression pressure was constant. Burning tests for determination of ignition time, flaming combustion temperature, flaming combustion duration, smoldering combustion duration, and mass loss during burning were made according to DIN4102 standards. According to the results of the tests, adhesive type did not affect ignition time and mass loss. While flaming combustion temperature of PB with UF was 19% higher, flaming combustion duration and smoldering combustion duration was 32% and 29% lower than those of PB with MF, respectively. While ignition time of PB with GW was 50% higher than that of PB with RW, changes in burning properties were similar for both PBs. An increase in the content of GW and RW affected burning properties of PB positively and an increase of ignition time up to 196% were obtained.Öğe Panel mobilya imalatında kullanılan bazı makinelerde owas yöntemi ile eylemsel duruş analizi(2012) Ülker, Onur; Burdurlu, ErolBu çalışmada, panel mobilya üretiminin kısmi sürecinde kullanılan daire testere, kenar bantlama ve dikey delik makinelerinde çalışanların vücut elemanlarının çalışma anındaki duruşlarının yüklenme ve zorlanma durumlarına göre kategorilendirilerek analizi hedeflenmiştir. Çalışma, Ankarada faaliyet gösteren küçük ölçekli bir işletmede gerçekleştirilmiştir. Çalışma duruşlarının kategorilendirilmesinde OWAS (OvakoWorkingPosturesAnalyzingSystem) yönteminden yararlanılmıştır. Yönteme uygun olarak, süreç 30 dk süreli olarak videoya kaydedilmiş ve çalışanların vücut elemanlarının duruşları tehlike durumuna göre kategorilendirilmiştir. Yüksek yüklenme ve zorlanma kategorisindeki duruşlarla ilgili olarak süreçte değişiklikler yapılarak süreçler yeniden videoya kaydedilmiş çalışma duruşları analiz edilip tekrar kategorilendirilmiştir. Yapılan düzenlemelerin tehlike kategori değerlerinde toplamda % 37lik bir azalma sağladığı tespit edilmiştir.Öğe Some mechanical properties of densified and laminated Lombardy poplar (Populus nigra L.)(Slovak Forest Products Research Inst, 2016) Ulker, Onur; Burdurlu, ErolIn this study, it was studied the effects of densification and then lamination processes on some mechanical properties of Lombardy poplar (Populus nigra L.), which is one of the low density tree species. Densification temperatures were 80, 100, 120 and 140 degrees C and ratios of densification were 15, 30 and 50 %. Furthermore, lamellas with a thickness of 4 mm cut from densified materials were laminated by bonding one on top of the other with urea formaldehyde (UF) and polyvinyl acetate (PVAc) adhesives. Bending, modulus of elasticity, compression and tensile tests were applied by preparing specimens from the pieces. According to test results, the most suitable temperature level was 120 degrees C. As the ratio of densification was increased at this temperature level, increase were observed in the mechanical properties. Also, lamination provided significant increases in the mechanical values compared to laminated but undensified Lombardy poplar. Increases were observed in the mechanical properties reaching 444 % with application of densification and lamination processes.
