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This current research work was aimed to develop an innovative panel by combining the nail-laminated timber (NLT) and cross-laminated timber (CLT) into a single product named nail-cross-laminated timber (NCLT) to take advantage of both structural panel products in a single product as a structural member. To investigate the mechanical properties of the NCLT, its bending performance and rolling shear were examined and compared to those of conventional CLT and NLT floor panels. The NCLT and the CLT panels were fabricated in 3 layers such as the CLT. Polyurethane adhesive was used on the laminations. The cross layers of the NCLT were made of a 30-mm-thick vertically laminated NLT. The NLT floor panels were fabricated by vertically n
The objective of this study was to investigate the physical and mechanical properties of glulam made from compressed poplar wood (Populus deltoides) by technique of Combined Hygro-Thermo-Mechanical Treatment (CHTMT) which is combination of two techniques of hygrothermal treatment and densification of wood. The poplar wood blocks were initially treated hygrothermally at temperatures of 130, 150, and 170?C for holding times of 20 and 40 minutes. Afterwards, the densification process was carried out under a hot press (at 160?C for 20 minutes) at two levels of compression set, i.e. 40 and 60 percent based on the blocks thickness (radial direction). For production of glulam, the blocks were jointed together by finger joint and polyurethane resin
Wood coating with clear coats such as polyacrylate have a short service life since solar radiations pass through the coat and cause subsequent discoloration of wood surface. These phenomena can be decreased by using suitable UV absorbants in the coats. Therefore, in this research, olive leaf extract in combination with nano-particles of titanium dioxide (TiO2) and zinc oxide (ZnO) were added to the polyacrylate coat as the substrate to study the possible effects of different formulated coats on surface properties of the thermally modified wood after exposure to the natural weathering for a long period. The surface properties of the coated wood such as color change, surface roughness and wettability of the coated wood were studied during the
Combined hygro-thermo-mechanical technique was adopted and used for densification of poplar wood instead of sole treatment. This technique is combination of two techniques of hygrothermal treatment and densification of wood. For treatment, poplar wood blocks were initially treated hygrothermally at temperatures of 130, 150 and 170 C for holding time of 20, 40 minutes. Afterwards, the densification process was carried out under a hot press (temperature 160 C for 20 minutes). For densification compression set was adjusted for 40 and 60% based on the initial thickness (radial direction) of the blocks. The densified and non-densified wood blocks were tested for physical and mechanical properties as density, water absorption, thickness swelling,
In this research, two different types of commercial tannins, namely a hydrolysable tannin (chestnut) and a condensed flavonoid tannin (mimosa), were used to prepare two types of soy-based (soy flour (SF) and soy protein isolate) adhesives for making plywood. Thermogravimetric properties (TGA) and its derivative as function of temperature (DTG) of different soy-based adhesive were measured in the range 40?C–300?C. Thermomechanical analysis (TMA) from 25?C to 250?C was done for the different resin formulations. Duplicate three-ply laboratory plywood panels were prepared by adding 300 g/m2 of the adhesives’ total resin solid content composed of SF or isolated soy protein (ISP), urea, chestnut, and mimosa tannin extracts with hexamine as ha
Meticulous chemical analysis of decaying xylem and linking it to corresponding anatomical modification at the cellular level can improve our understanding of the decay process. The aim of this study was to monitor the histological, chemical, photochemical, and progression of wood degradation by two white-rot fungi at different intervals. Oriental beech wood (Fagus orientalis) blocks were exposed to Pleurotus ostreatus and Trametes versicolor to investigate the degradation capabilities of these two fungi. Light microscopy was used to study the decay patterns in wood. Decayed wood samples were also analyzed to determine lignin, cellulose and sugar contents and also evaluated at two week intervals by FT-IR spectroscopy to study chemical altera
In this research tannic acid was used to prepare soy-based adhesives for making plywood and fiber board. The different resin formulations were analyzed by Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and its derivative as a function of temperature (DTG) and Fourier Transform Infra-red (FTIR) spectroscopy. The results showed that the addition of tannic acid to soy-based adhesive decreased soy-based adhesive viscosity and its pH. The DSC analysis showed that the denaturation temperature of soy-based adhesives decrease by adding tannic acid. The TGA and DTG curves showed that the thermal degradation of soy flour starts above 146? C. The FTIR spectroscopy results also showed that the soy flour amino acids appeared t
In this research, technological properties of glulam beams made from hydrothermally treated poplar (Populus deltoides) wood were investigated. Poplar wood blocks with dimensions of 6 (r) ? 10 (t) ? 73 (l) cm3 were cut and hydrothermally treated in a stainless steel reactor at temperatures of 140 and 160?C for a holding time of 30 min. The treated wood blocks were initially air seasoned and then they were dried in a semi-pilot scale vacuum dryer to achieve moisture content (MC) of 12%. Conditioning of the treated and the untreated wood blocks was done prior to adhesive bonding. Afterwards the glulam beams (4 ply) were manufactured using polyurethane. In order to evaluate the physico-mechanical properties of the beams, density, eq
Hydrothermal treatment was considered as a method for modification of oriental beech wood to be used as reinforcing filler for natural rubber. Surface energy of treated wood fibers and their interaction with natural rubber were studied by water contact angle of wood and dynamic-mechanical-thermal analysis of formed bio-composites and compared with those for untreated and silane-treated wood fibers. Hydrothermal treatment of wood was performed at two temperatures of 140??C and 160??C, and bio-composites were prepared by melt mixing method. Results showed that water contact angle of untreated wood increases by hydrothermal treatment and silane modification of wood fibers, which the latter has the highest value. Dynamic-mechanic
Wettability and some other physical and mechanical properties of cellulose films are as restricting factors in application of such biodegredable films. Since it is proposed that the dissolution process parameters may significantly affect the cellulose film structure and properties, in this research, the effect of dissolution time on wettability and some substantial properties of cellulose film was evaluated. In this due, cotton linter was dissolved in 1-butyl 3-methyl imidazolium chloride for 1, 3 and 5 hours, and following being washed with distilled water as an anti-solvent, the cellulose films were casted on petri-dishes and dried in 60 C oven. In order to research the effect of dissolution time on chemical and physical structure of the
In this research, soy flour-tannin adhesives were successfully used in particleboard preparation. Tow types of tannins ie mimosa (as condensed tannin) and chestnut (as hydrolysable tannins) were used for soy resin modification. For this purpose, mimosa and chestnut tannins were added to soy adhesive with 5, 10 and 15 percent based on dry weight of soy flour. 9 percent Glyoxal was used based on dry weight of tannin to accelerate the tannin reaction with soy flour components. Prepared soy-tannin adhesives were used in particleboard manufacturing with 350 300 14 mm3 dimansion and 0.7 g/cm3 nominal density. Results of viscosity measurement showed that the addition of each tannin decreased viscosity of soy adhesive. In this study, result of ther
It was planned to study the surface properties of the oak wood coated with stearic acid and post-heated in press and oven to compare it with a coated surface with typical resin Killer-Sealler polyester to indicate any effects of the stearic acid on wood surface. The properties; as contact angle as well as color changes of the oak wood were studied and determined in the current research work. Those properties were determined before and after ten days of leaching tests to reveal resistance of the stearic acid on wood. FTIR spectroscopy was carried out on wood surface to detect any reaction with wood surface. The results revealed that wood surface became hydrophobic due to coating with stearic acid and post-heating with hot press as well as ov
Moisture induced stresses were studied in glulam beams, which were made from hydrothermally treated poplar (Populus deltoides) wood in the current research work to understand whether the hydrothermal wood modification can reduce those stresses or not. Wood blocks with dimensions of 6 (R)?× 10 (T)?× 73 (L)?cm3 were cut and hydrothermally treated in a stainless steel reactor at temperatures of 140 and 160??C for a holding time of 30?min. The treated wood blocks were dried to achieve moisture content of 12%. Afterwards, the glulam beams (4-ply) were manufactured by using polyurethane (PUR) adhesive. In order to evaluate cross sectional moisture induced stresses (MISes) and bending properties of glulam beams; wood density, equilibrium moist
The present research work has investigated the physical and mechanical properties of hygrothermally modified poplar (Populus deltoides L.) wood. The poplar wood blocks were treated hygrothermally at temperatures of 130, 150 and 170 o C and for 20, 40 minutes treatment time. The physical and mechanical properties were determined for both treated and untreated wood. The properties; mass loss, collapse, specific gravity changes, dimensional stability, surface roughness, bending strength and modulus of elasticity, were determined prior to and after the treatment in all wood blocks. The hygro-thermal treatment significantly improved the dimensional stability of the samples. It was also found that the hygro-thermal treatment increased collapse, s
In this research soy flour- tannin adhesives were used in particleboard preparation, successfully. Tow type of different tannins Mimosa (as condensed tannin) and Chestnut (as hydrolysable tannins) were used for soy resin modification. For this purpose, mimosa and chestnut tannin were added to soy adhesive with 5, 10 and 15 percent based on dry weight of soy flour. 9 percent Glyoxal was used based on dry weight of tannin for accelerate tannin reaction’s with soyflour components. Prepared soy-tannin adhesives were used in particle board manufacturing with 350?300?14 mm3 dimansion and 0.7 g/cm3 nominal density. Results of viscosity measurment showed that addition of each of tannins decreased visocosity of soy adhesive. In this study, result