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    Effects of heat treatment and surface roughness on bonding strength
    (Elsevier Sci Ltd, 2012) Ozcan, Suleyman; Ozcifci, Ayhan; Hiziroglu, Salim; Toker, Hilmi
    The objective of this study was to determine the effect of heat treatment on bonding strength of the samples from four different species, namely Scotch pine, oriental beech, white oak and Uludag fir woods. The samples were exposed to three temperature levels of 120 degrees C, 150 degrees C and 180 degrees C for time periods of 2 and 6 h. Based on the findings in this work white oak samples had the highest average roughness (R-a) and maximum roughness (R-max) values of 9.49 mu m and 48.9 mu m, respectively. It appears that heat treatment enhanced overall surface quality of the samples. (C) 2012 Elsevier Ltd. All rights reserved.
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    EFFECTS OF SILICA GEL ON LEACHING RESISTANCE AND THERMAL PROPERTIES OF IMPREGNATED WOOD
    (Slovak Forest Products Research Inst, 2010) Altun, Suat; Ozcifci, Ayhan; Senel, Ahmet; Baysal, Ergun; Toker, Hilmi
    The aim of this study was to increase the resistance of fire retardant chemicals for leaching in order to improve the fire resistance of wood. For this purpose, Scots pine (Pinus sylvestris L.) and Chestnut (Castanea sativa Mill.) wood impregnated with 3 % aqueous solutions of boric acid, zinc chloride and aluminum chloride at 60 C by using vacuum- press impregnating method according to ASTM D1413-07 standard. In order to increase leaching resistance of the chemicals, wood samples post-treated with sodium silicate and then sodium bicarbonate to form insoluble silica gel in wood. After leaching test, it was determined that silica gel treatment decreased the amount of leachant in all three impregnation solutions. Effect of silica gel on the thermal behavior of treated samples was determined via termogravimetric analysis (TGA). According to the results of TGA silica gel treatment improved the fire resistance property of wood especially in boric acid treated wood.
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    EFFECTS OF SOME ENVIRONMENTALLY-FRIENDLY FIRE-RETARDANT BORON COMPOUNDS ON MODULUS OF RUPTURE AND MODULUS OF ELASTICITY OF WOOD
    (State Forest Products Research Inst, 2009) Toker, Hilmi; Baysal, Ergun; Simsek, Hakan; Senel, Ahmet; Sonmez, Abdullah; Altinok, Mustafa; Ozcifci, Ayhan
    This study was designed to determine some mechanical properties such as modulus of rupture (MOR) and modulus of elasticity (MOE) of wood treated with some environmentally-friendly fire-retardant boron compounds. Sodium perborate (SP) boric acid, (BA), and borax (BX) were used as boron compounds. Wood specimens were prepared from Calabrian pine (Pinus brutia Ten.) and beech (Fagus orientalis Lipski) wood. Before MOR and MOE tests, wood specimens were impregnated with aqueous solutions (1, 2, 3, 4, 5, and 6 %) of berates according to ASTM D 1413-76. Our results showed that MOR values of wood specimens treated with borates were lower compared to untreated control specimens. The MOR and MOE values of wood specimens were the lowest for treatments with SP followed by BX and BA, respectively. In general, the higher concentration levels of borates, the lower MOR of wood resulted.
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    THE EFFECTS OF SOME IMPREGNATION PARAMETERS ON MODULUS OF RUPTURE AND MODULUS OF ELASTICITY OF WOOD
    (Slovak Forest Products Research Inst, 2011) Ozcifci, Ayhan; Ayar, Serdar; Baysal, Ergun; Toker, Hilmi
    The aim of this study was to determine the effects of some impregnation parameters such as impregnation chemicals, impregnation durations, and impregnation methods on modulus of rupture (MOR) and modulus of elasticity (MOE) of Oriental beech (Fagus orientalis Lipsky) and Scots pine (Pinus sylvestris L.). Wood specimens were prepared according to TS 2470 and impregnated with chemicals for 2, 4, and 6 hours by dipping and vacuum-pressure methods. Imersol aqua, aqueous solutions of zinc chloride, and borax were used as impregnation chemicals. After impregnation, the MOR and MOE of wood specimens were determined. Results showed that the MOR and MOE of wood specimens were the lowest for the ones impregnated with imersol aqua followed by zinc chloride and borax, respectively. There were no statistically significant differences in MOR and MOE values among all impregnation durations and methods.
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    Fire properties of laminated veneer lumber treated with some fire retardants
    (State Forest Products Research Inst, 2007) Ozcifci, Ayhan; Toker, Hilmi; Baysal, Ergun
    The objective of this study was to determine fire properties of laminated veneer lumber (LVL) prepared from beech (Fagus orientalis Lipsky) veneers treated with some fire retardants. Boric acid (BA), borax (BX), and di ammonium phosphate (DAP) were used as impregnation chemicals, which are the most commonly used fire retardants in wood preservation industry. Tanalith-C 3310 was also used for comparison. Laminated veneer lumbers were manufactured using the melamine formaldehyde (MF) and phenol formaldehyde (PF) adhesives. Fire test method was performed in three stages: flame stage, without flame stage, and glowing stage. Results indicated that the lowest temperature for flame stage, without flame stage, and glowing stage were obtained for the specimens glued with MF and treated with DAP and (BA-BX) mixture. The lowest mass loss was found for the specimens glued with MF and treated with DAP and (BA-BX) mixture. Tanalith-C 3310 didn't improve fire resistance of the LVL specimens.
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    GLOSSINESS, COLOR STABILITY, AND SURFACE ROUGHNESS OF WOOD TREATED WITH SOME BLEACHING CHEMICALS
    (State Forest Products Research Inst, 2009) Ozcifci, Ayhan; Yapici, Fatih; Altun, Suat; Toker, Hilmi; Baysal, Ergun; Senel, Ahmet; Simsek, Hakan
    The aim of this study was to determine the effects of different bleaching chemicals and their treatment time on glossiness, color stability, and surface roughness of wood. Spruce (Picea orientalis L.) and oak (Quercus sessiliflora Salisb.) wood specimens were bleached with aqueous solutions of 25% hydrogen peroxide (H(2)O(2)), 25% ammonia (NH(3)), and their mixture (1:1;volume:volume) for 10, 20, and 30 minutes immersing. Glossiness of wood specimens parallel and perpendicular to grain values were measured with Glossmeter at 60-degree incident angle. Color measurements and surface roughness were wade according to ISO 7724 - 2, and ISO 4287 standards, respectively. Results showed that the highest glossiness decrease (0.99) was observed in oak wood treated with ammonia solution perpendicular to grain for 20 min. immersing. The highest total color chance (18.88) was observed in oak wood treated with ammonia solution for 30 minutes immersing. All bleaching solutions increased the surface roughness of wood specimens.
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    Influence of weathering on adhesion strength of chemically treated and coated Scotch pine
    (Elsevier Science Sa, 2012) Toker, Hilmi; Hiziroglu, Salim; Ozcifci, Ayhan
    The objective of this study was to evaluate the effect of weathering on adhesion strength of Scotch pine (Pinus sylvestris L.) samples treated with three concentrations of Tanalith-E. Treated samples were also coated with polyurethane, synthetic and water based varnishes prior to 500 h accelerated weathering test. Adhesion strength between varnishing materials and substrate samples was determined employing pull-off type equipment. Based on the findings in this work adhesion strength values of samples decreased with increasing concentration of treatment chemical. The highest average strength value was found as 3.48 MPa for untreated control samples while 2.88 MPa was the lowest average value for the samples treated with Tanalith-E having 9% concentration and coated with water based varnish. Majority of the failures took place within the adhesion line between coating and the substrate with a very limited torn fibers. Results of statistical analysis revealed that samples coated with three different types of varnishes did not show any significant difference from each other at 95% confidence level. It was also found that chemical treatment of the samples adversely influenced their overall adhesion strength characteristics. (C) 2011 Elsevier B.V. All rights reserved.
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    AN INVESTIGATION ON COMPRESSION PARALLEL TO GRAIN VALUES OF WOOD IMPREGNATED WITH SOME BORON COMPOUNDS
    (Slovak Forest Products Research Inst, 2008) Toker, Hilmi; Baysal, Ergun; Ozcifci, Ayhan; Altinok, Mustafa; Sonmez, Abdullah; Yapici, Fatih; Altun, Suat
    This study was carried out to determine compression strength parallel to grain of wood impregnated with some boron compounds. Sodium perborate (SP) boric acid, (BA), and borax (BX) were Used as boron compounds. Wood specimens were prepared from Calabrian pine (Pinus brutia Ten.) and beech (Fagus orientalis L.) wood. Before compression test parallel to grain, wood specimens were impregnated with aqueous solutions (1, 2, 3, 4, 5, and 6 %) of boron compounds according to ASTM D 1413(1976). Results showed that compression strength parallel to grain values of wood specimens treated with boron compounds were lower compared to untreated control specimens. Borate treatments reduced compression strength parallel to grain of wood in significant level compared to untreated control. The compression strength parallel to grain values of wood specimens were the highest for untreated control specimen followed by BA, BX, and SP treated wood specimens, respectively. In general, our results showed that the higher concentration levels of boron compounds, the lower compression strength parallel to grain values of wood resulted.
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    Some combustion parameters of wood impregnated with borates
    (Forest Products Soc, 2009) Toker, Hilmi; Baysal, Ergun; Ozcifci, Ayhan; Simsek, Hakan; Altun, Suat; Yapici, Fatih; Goktas, Osman
    This study was conducted to determine some of the combustion parameters of Calabrian pine and Oriental beech treated with borates. Average mass loss and temperature values of Calabrian pine and Oriental beech wood were determined according to ASTM E-69. Boric acid, borax, and sodium perborate were used as borates. Before the combustion test, wood specimens were impregnated with aqueous solutions (1%, 2%, 3%, 4%, 5%, and 6%) of borates according to ASTM D1413-76. These results showed that mass loss and temperature values of both wood specimens treated with borates were lower compared to the untreated control specimens. Higher concentration levels of borates resulted in lower mass loss and temperature values of the wood.