Browsing by Author "Ulay, Goksel"

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Application of Synthetic-Based Furniture Varnish To Various Wood Species: Comparison of Color Parameters
(North Carolina State Univ dept Wood & Paper Sci, 2025) Ulay, Goksel; Peker, Huseyin; Ayata, Umit
Synthetic-based furniture varnish (colorless and glossy) was applied in two coats using a brush to the following wood types: lemon (Citrus limon (L.) surfaces were compared. The analysis of variance results for all color parameters revealed significant effects for wood type, varnish application, and their interaction. When the AE* values derived from color formulas were sorted from the lowest to the highest, they were ordered as follows: lemon, black pine, kotibe, loquat, and iroko. After varnish application, decreases in L* values were observed across all wood types, while increases in b* and C* values were detected. In black pine wood, the a* and h degrees values increased. Additionally, for iroko, loquat, and kotibe woods, there was an increase in the a* parameter, while h degrees values decreased for these wood types. Overall, the varnish application resulted in color changes in the wood materials.
Determination of Color Characteristics of Some Wood Species Treated With Bleaching Chemicals
(North Carolina State Univ dept Wood & Paper Sci, 2023) Cakicier, Nevzat; Ulay, Goksel
With the application of bleaching treatments, the color of the wood material changes. When different bleaching agents are applied to the same wood, different results are likely to be obtained. In this study, wood species doussie (Afzelia africana), iatandza (Albizia ferruginea), merbau (Intsia bijuga (Colebr.) O. Kuntze), mahogany (Swietenia mahagoni L.), and hornbeam (Carpinus betulus L.) along with one and two component (B -One-C and B-Two-C) wood bleaching chemicals were applied to the wood material surfaces with sponge technique. Then, color parameters (ho: hue angle, a*: red color tone, b*: yellow color tone, C*: chroma, and L*: lightness) were determined on bleached and unbleached materials. According to the results obtained, B-One-C application increased ho, a*, b*, C*, and L* values in all wood species. The highest increment E* values were determined in mahogany, doussie, hornbeam, and merbau wood species treated with B-Two-C. The chemicals used in the study showed different results on the same wood.
Effect of Pumice Powder on Mechanical, Thermal, and Water Absorption Properties of Fiberboard Composites
(Lukasiewicz Research Network - Lodz institute of Technology, 2023) Koyuncu, Menderes; Ulay, Goksel; Seker, Ulvi
Composites were produced using medium-density fiberboard (MDF) flour with pumice powder which was mixed at various ratios by the hand lay-up technique. Mechanical properties, such as tensile and three-point bending strengths, were determined by ASTM D3039 and ASTM D790 respectively. The best three-point bending and tensile strength properties were maximum values obtained from composites containing 20wt% pumice powder (pp) and 50wt% pumice powder (pp) respectively. It is observed that the water absorption rate into the composites decreases with an increase in the pumice powder-to-ratio. The composite filled with 50wt%pumice powder absorbed the least amount of water compared to the other composites. All composites were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and differential scanning calorimetry analysis (DSC). SEM images revealed a near-homogeneous surface partly free of defects and holes. However, lateral profile images showed the presence of MDF flour particles agglomerated and a considerable number of bubbles and cavities that could interfere with the mechanical properties of the composites. The results of the mechanical, and thermal properties suggested that pumice powder epoxy composites with MDF flour can increase their tensile, three-point-bending strength, and glass transition temperature for the pure MDF flour composite.
Effect of Thermal Modification and Picture Varnish Application on Color Change of Scots Pine (Pinus Sylvestris L.) Wood
(Lukasiewicz Research Network, Poznan inst Technology, 2025) Peker, Huseyin; Ayata, Umit; Ulay, Goksel
Scots pine is one of the important tree species used by the wood processing industry in many countries for both interior and exterior applications. It is well known that thermal treatment alters the color of wood. To protect wood from outdoor environmental conditions, certain chemicals are applied to its surface. These protective chemicals also influence the color of thermally treated wood. In this study, the color-altering effect of picture varnish (refined linseed oil), commonly used as a protective chemical in the field of painting, was investigated on both thermally treated and untreated wood materials. Scots pine (Pinus sylvestris L.) wood samples were subjected to thermal treatment at 212 degrees C for 2 h. Following this, varnish made from refined linseed oil was applied to some of these samples and some untreated samples, with the remaining untreated samples used as controls. Color and whiteness index (WI*) values were analyzed on the resulting four different materials, and the results were compared. Analysis of variance showed significant effects for the factors of heat treatment, picture varnish application, and their interaction, on WI* (& boxV; and perpendicular to), a*, L*, ho, b*, and C* values. In the non-heat-treated samples, the application of varnish resulted in reductions in WI* values in both directions and in L* values, while increases were observed in ho, b*, C*, and a* values. Additionally, the application of varnish to the heat-treated samples resulted in an increase in a* values, while reductions were observed in WI* values in both directions, as well as in ho, L*, b*, and C* values. After heat treatment, the triangle E* value for Scots pine wood was calculated as 33.63. For both heat-treated and non-heat-treated samples, varnish application resulted in negative triangle L* values and positive triangle a* values. Additionally, triangle b* and triangle C* values were positive in the non-heat-treated and varnished samples, while they were negative in the heat-treated and varnished samples. The protective picture varnish used in the study significantly altered the color of both thermally treated and untreated wood.
The Effect of Weathering on Color and Glossiness Properties of Polyurethane-Modified Water-Based Varnish Layers Applied to Thermally Treated Ash Wood
(North Carolina State Univ Dept Wood & Paper Sci, 2025) Ulay, Goksel; Akter, Mete; Cakicier, Nevzat; Peker, Huseyin; Ayata, Umit; Atilgan, Abdi; Ciftci, Seymen
The effects of artificial weathering (168, 336, and 504 h) on the glossiness values and color parameters of varnished, polyurethane-modified ash wood were investigated. Samples included control samples without treatment and thermally treated samples under two different conditions (190 degrees C for 1.5 h and 212 degrees C for 2 h), all coated with a polyurethane-modified water-based varnish. In non-thermally treated and varnished samples, decreases in L* values were observed after weathering, while increases were noted in h(o), C*, b*, and glossiness at 60 degrees in both perpendicular and parallel directions to the fibers. After weathering, for samples thermally treated at 190 degrees C for 1.5 h and varnished, increases were observed in glossiness values at 20 degrees and 60 degrees in both directions, as well as in L*, b*, and h(o) values. Conversely, decreases were noted in a* and C* values. In samples thermally treated at 212 degrees C for 2 h and varnished, increases in a*, L*, h(o), b*, and C* values were detected after weathering, whereas decreases were observed in glossiness at all angles (20 degrees and 60 degrees) in both directions. The triangle E* values showed a decreasing trend in non-thermally treated varnished samples after weathering, while an increase was observed in samples thermally treated at 212 degrees C for 2 h and varnished.
Effects of Artificial Weathering on Some Surface Properties of Anatolian Chestnut (Castanea Sativa Mill.) Wood Applied With Yacht Varnish
(North Carolina State Univ dept Wood & Paper Sci, 2023) Ulay, Goksel
Anatolian chestnut wood is an industrial material used in various indoor and outdoor applications in Turkey. This study investigated the effects of artificial weathering (times: 144, 288, 432, and 576 h) conditions on color parameters (L*, Delta L*, a*, Delta a*, b*, Delta b*, Delta E*, h(o), Delta H*, C*, and Delta C*), glossiness values at 60 degrees in different directions (parallel to and perpendicular to), pendulum hardness (Konig method) values, and surface adhesion strength (pull-off method, MPa) on the layers of yacht varnishes applied to Anatolian chestnut (Castanea sativa Mill.) wood. The results showed that the univariate analysis of variance was significant by obtaining the weathering factor for all tests. While the brightness values perpendicular (perpendicular to) and parallel (parallel to) to the fibers increased at 144 and 288 h, they decreased at 432 and 576 h. Adhesion strength to the surface decreased 4.35% at the 576th h of weathering. At the end of weathering, a*, C*, b*, and pendulum hardness values increased, while h(o) and L* values decreased compared to un-weathered samples. The Delta a* and Delta E* values increased with increased weathering time.
Effects of Formaldehyde Scavenger on Mechanical, Physical, and Emission Test Results in Multi-Layer Pressed Chipboard Production
(Inst Technol Drewna, 2025) Camlibel, Osman; Peker, Huseyin; Ayata, Umit; Ulay, Goksel
This study investigates the effects of different formaldehyde scavenger (FS) ratios on the physical, mechanical, and chemical properties of fiberboard composites. Experimental analyses included measurements of thickness, density, modulus of rupture (MOR), modulus of elasticity (MOE), internal (WA), and formaldehyde emission (FE) levels. The results indicate that an increase in the FS ratio leads to a significant decline in mechanical properties. Specifically, MOR, MOE, and IB values decreased by 17.97%, 15.65%, and 16.33%, respectively. Changes in TS and WA were also observed, with TS increasing by up to 22.68% and WA decreasing by as much as 16.90%. In terms of formaldehyde emissions, a significant reduction was observed as the FS ratio increased. At a 15% FS ratio, formaldehyde emissions decreased by 43.24%, which is considered a positive outcome in terms of environmental and health impacts. Overall, the use of FS in specific ratios reduces FE while causing certain reductions in mechanical properties. These findings highlight the importance of optimizing FS usage for the production of low-FE fiberboards.
The Effects of Protective Dye Layer Applied on Varnish Layer Hardness, Scratch Resistance and Glossiness of Various Blockboard Types
(Academic Journals, 2011) Cakicier, Nevzat; Korkut, Suleyman; Korkut, Derya Sevim; Kurtoglu, Ahmet; Erdinler, E. Seda; Ulay, Goksel
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 30 test samples prepared as coated or uncoated with paper with 10 x 10 x 1.6 cm sizes from blockboard, the surface hardness values of the protective layer as applied in ASTM D 436695 (1984) were determined, the scratch resistance were determined according to the essentials specified in TS 4757 (1986), and the glossiness were also determined according to the essentials specified in TS 4318 EN ISO 2813 (2002). According to the result of the study, concealing dyeing is obtained with much surface hardness, scratch resistance and glossiness 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 Influence of Artificial Weathering on the Adhesion of Some Varnishes Applied to Thermally Treated Iroko and Ash Woods
(Taylor & Francis Ltd, 2025) Ulay, Goksel; Cakicier, Nevzat
In this study, waterborne and solventborne varnishes were applied to the surfaces of ash (Fraxinus angustifolia Vahl.) and iroko (Chlorophora excelsa) woods which were heat treated at 190 degrees C for 1.5 h and 212 degrees C for 2 h according to the thermowood method. The influence of 576 h of aging process on varnish adhesion was determined by pull-off test according to ASTM-D 4541 in UVB-313 EL type aging device. As a result, wood species, varnish type and aging time were found to have a different level of influence on the adhesion strength of varnish layers. The highest adhesion value of 4.804 MPa was obtained in the sample with one-component waterborne varnish applied to ash wood, which was heat treated at 190 degrees C for 1.5 h and aged with UV-B lamp for 144 h.
Investigation of Color Parameters in Pine, Limba, Sapele, Iroko, Oak, and Beech Wood Species Exposed To Outdoor Conditions in Van City, Turkey
(North Carolina State Univ dept Wood & Paper Sci, 2023) Ulay, Goksel
Sapele, pine, limba, iroko, beech, and oak wood species are important species used indoors and outdoors, as supplied by furniture companies. It is known that the color changes in wood material when exposed to the external environment. This is an important factor for the outdoor use of wood material. In this study, the color parameters of Scotch pine (Pinus sylvestris L.), oriental beech (Fagus orientalis L.), limba (Terminalia superba Engl. et Diels), sapele (Entandrophragma cylindricum), sessile oak (Quercus petraea L.), and iroko (Milicia excelsa) wood species, which are used in both indoor and outdoor woodworking industries in Van city, Turkey were investigated after exposing them to natural weather conditions for 9 months in outdoor conditions. Each type of wood exhibited a different color behavior in outdoor conditions. In sapele and limba wood species, b* and a* values increased and L* values decreased with increasing weathering time. It was observed that Delta E* increased with increasing time of exposure in all tree species. At the end of 9 months of weathering, the highest Delta E* value was determined in pine wood, followed by beech, sapele, limba, iroko, and oak wood species, respectively.
Investigation of Interior Settings on High Earthquake Risk Areas (Case Study of Tosya)
(Kastamonu Univ, Orman Fak, 2017) Karamanoglu, Mehmet; Ulay, Goksel
As a country which takes part in the earthquake zone, Turkey has experienced so many earthquakes within its borders. Experts have made it clear that Turkey is likely to have similar earthquakes in different zones in near future. Since Tosya; Kastamonu is located on North Anatolian Fault Line and known as the first degree seismic zone, the city experienced many earthquakes in the past. According to the researches, avoidable many factors such as inappropriate building structures and interior designs, all led to the loss of life and property. A questionnaire has been applied to the people who live in Tosya, Kastamonu during the research and their furniture use habits have been taken in to consideration in terms of actions to be taken against earthquakes. Consequently awareness level of the people about the interior design of their houses which are located in the seismic zone has been brought out and some solutions and suggestions for the problems have been introduced.
Properties of Sandwich Wood-Based Composite Panels and Their Use in Furniture Industry
(Kastamonu Univ, Orman Fak, 2015) Ayrilmis, Nadir; Ulay, Goksel; Bagli, E. Fatih; Ozkan, Ibrahim
In wood products industry, the diversity of wood based panel products is increasing day by day, and composite (sandwich) materials in honeycomb and foam structure have an important place among these. The lightness, flexibility and resistance properties on the site of utilization are the major advantages of these products. Not only they are % 40-70 lighter in weight, resistant to humidity, easy to transport, recyclable and ecological, as compared to the traditional wood based panels such as MDF, OSB, and plywood, but also have sufficient mechanical properties. In this study, production, the advantages and disadvantages of sandwich-structured composite panels are presented. Information on the utilization of sandwich-structured composite panels in furniture industry has been provided and the studies on these products have been investigated.