Public Titles
Editorial
Wood Modification and Wood Preservation
Wood Modification and Wood Preservation
َAmir Mohamad Nahofteh Estarabadi; Davood Rasouli; Taghi Tabarsa; Abolghasem Khazaeian
Abstract
Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. ...
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Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. However, when preservative-treated wood is exposed to outdoor environments, it becomes susceptible to weathering and leaching. The use of coatings can be an effective method in this regard. This research investigates the effectiveness of two transparent coatings, acrylic and alkyd, in enhancing the weathering resistance of wood specimens treated with waterborne preservatives. .Methodology: defect-free poplar wood specimens with dimensions of 12×10×2 cm3 (L, T, R) were prepared and then they were treated with preservatives ACC, CCB, and ACQ-C using the full-cell/pressure impregnation method. Subsequently, acrylic and alkyd transparent coatings were applied to the surface of the specimens. After applying the coatings, the specimens were exposed to natural weathering for one year.Results: The results indicated that the type of coating significantly influenced the color and adhesion resistance of specimens. Furthermore, the research findings demonstrated that all specimens experienced color changes and a decrease in coating adhesion resistance due to weathering. Among the coatings, the intensity of color changes and deterioration in specimens with acrylic coatings was higher compared to those with alkyd coatings. Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood.Background and Objectives: Wood, as an organic material, is susceptible to deterioration by destructive factors such as fungi and insects. One approach to protect against these factors is the treatment of wood with preservatives. The use of waterborne preservatives is common due to the numerous advantages. However, when preservative-treated wood is exposed to outdoor environments, it becomes susceptible to weathering and leaching. The use of coatings can be an effective method in this regard. This research investigates the effectiveness of two transparent coatings, acrylic and alkyd, in enhancing the weathering resistance of wood specimens treated with waterborne preservatives. .Methodology: defect-free poplar wood specimens with dimensions of 12×10×2 cm3 (L, T, R) were prepared and then they were treated with preservatives ACC, CCB, and ACQ-C using the full-cell/pressure impregnation method. Subsequently, acrylic and alkyd transparent coatings were applied to the surface of the specimens. After applying the coatings, the specimens were exposed to natural weathering for one year. .Results: The results indicated that the type of coating significantly influenced the color and adhesion resistance of specimens. Furthermore, the research findings demonstrated that all specimens experienced color changes and a decrease in coating adhesion resistance due to weathering. Among the coatings, the intensity of color changes and deterioration in specimens with acrylic coatings was higher compared to those with alkyd coatings.Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood. .Conclusion: In general, it can be concluded that alkyd coatings exhibited better preservative performance against weathering for preservative-treated wood. .
Research Paper
Composite wood products
Haniye Shurvazi; Mohammad Shamsian; Ali Bayatkashkoli; Mohammad Dahmardeh Ghaleno
Abstract
Background and purpose: This study was conducted with the aim of investigating parallel strand lumber (PSL) made from reed waste and laminated veneer lumber (LVL) obtained from poplar wood that reinforced with glass fiber reinforced polymer (FRP) and epoxy resin.Materials and methods: The independent ...
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Background and purpose: This study was conducted with the aim of investigating parallel strand lumber (PSL) made from reed waste and laminated veneer lumber (LVL) obtained from poplar wood that reinforced with glass fiber reinforced polymer (FRP) and epoxy resin.Materials and methods: The independent variable was LVL and PSL with FRP and their comparison control sample without FRP. The mechanical properties of the manufactured boards including bending strength (MOR) and modulus of elasticity (MOE) in the width and edge of the test sample, shear strength, compression strength parallel to the grain, internal bonding and Screw Withdrawal Strengths were investigated as dependent variables. The obtained results were analyzed in the form of completely randomized design by SPSS software.Results: Results showed that of all of the studied mechanical properties, the use of FRP strengthened the PSL and LVL panels. For LVL, the effect of strengthening the samples with FRP was significant at the level of 1% and also for the modulus of rupture of the width and edge samples showed an increase of 93% and 59%, respectively. The value of MOE during reinforcement with FRP showed an increase of 89.6 and 132% for the width and length of the PSL samples, respectively. For LVL, the MOE value of the width and edge of the samples increased by 54 and 95.5% with reinforcement. Reinforced PSL samples have improved their shear strength by 31%, while this value is only 2.5% for LVL. in the internal bonding test, strengthening with FRP improved the internal bonding strength of the samples by 92%. Screw Withdrawal Strengths improved by 27% due to the strengthening of the test samples with FRP.Conclusion: According to the obtained results, it can be stated that the use of glass fibers and epoxy resin has a significant positive effect on the mechanical resistance of PSL made of reed and LVL and it is possible to use low quality raw materials such as reed and waste poplar wood layers.
Physics and Mechanical Wood
Physics and Mechanical Wood
mohammad najafianashrafi; ali Heidari; Hamed Jafarzadeh
Abstract
Background and goal: walnut tree (Juglans regia L.) are cultivated in many countries in Asia, Europe and United States. This tree has high resistance with beautiful pattern and are used in furniture industry, building panels, flooring and covering. Iran are ranked third in the world in the production ...
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Background and goal: walnut tree (Juglans regia L.) are cultivated in many countries in Asia, Europe and United States. This tree has high resistance with beautiful pattern and are used in furniture industry, building panels, flooring and covering. Iran are ranked third in the world in the production of walnut fruit after China and US. Thus, with considering high production of this tree in Iran and its diverse application in different industries, a comprehensive studding for physical and mechanical properties of this species in different regions of Iran seems necessary.Materials and methods: Walnut tree (Juglands regia L.) from two different regions, one from northeast (Mashhad) and the other from northwest (Maku) of Iran was selected for this study. Three trees from each region were selected randomly and cut with almost with the same diameter for physical and mechanical experiments. Samples also were cut from 2-4 meter from the ground. ISO 3129 and ASTM (D143-14) were used for doing physical and mechanical experiments respectively and at the humidity of 12%. Statistical analysis of data was performed using Graphpad prism version 8 and t-Test was performed for significant difference of data.Results: The average dry density of both Mashhad and Mako walnut wood was 0.625 and 0.579 g/cm3 respectively. There were a significant difference for both tangential shrinkage with values of 9.77 and 8.78 and volumetric shrinkage with measurement of 16.26 and 15.42 in Mashhad and Mako respectively. However, there was no significant difference for longitudinal and radial shrinkage in both walnut wood of the two regions. Walnut wood cut from Mashhad region showed higher physical and mechanical properties. The results of the mechanical characteristics of walnuts from two regions showed bending strength 100.54 and 87.61N/mm2 and elasticity modulus 10049.59 and 7504.21 N/ mm2 for Mashhad and Mako regions respectively which were significant. Results also showed not significant difference for compression parallel to the grain with values of 37.91 and 33.88N/mm2, for shear parallel to the grain with values of 9.15 and 8.95N/mm2, for Tensile strength parallel to the grain with 127.97 and 125.83 N/mm2, for Screw withdrawal strength in tangential values of 4031.01 and 3685.97N and Screw withdrawal strength in radial values of 4218.63 and 3915.03N and impact strength with the values of 27.81 and 25.24KJ/m2 for Mashhad and Maku regions respectively. Results also showed that the density of walnut wood in the two regions of Iran was similar to the those in Italy and eastern Europe but the mechanical properties of walnut tree such as bending strength and elasticity modules measured from Mashhad region was similar to the wone in turkey.Conclusion: The results showed that the physical and mechanical resistance of walnut wood located in Mashhad is higher than Maku wood, which was attributed to the higher dry density and the difference in weather conditions. Considering the appropriate mechanical resistance of walnut wood from both regions of Iran, this wood can be used in coating and furniture industries, building panels and flooring.
Research Paper
Chemistry of wood
Ramin Vaysi
Abstract
Background and aim: As a result of population growth, paper and wood products consumption has increased, and restrictions on using forest wood raw materials initiated the utilization poplar trees as fast-growing spices. The aim of this study was to focus on identification and comparison of the ...
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Background and aim: As a result of population growth, paper and wood products consumption has increased, and restrictions on using forest wood raw materials initiated the utilization poplar trees as fast-growing spices. The aim of this study was to focus on identification and comparison of the phenolic chemical components in poplar woods (Populus nigra and Populus deltoides).
Materials and methods: In this study, three trees from each poplar tree were randomly felled in plantation near Nowshar, Iran. Then three discs were cut from each log. At first, wood was grounded and then wood flour extractive were measured using TAPPI standard procedure. Wood flour was extracted by acetone and extractives residue was added to BSTFA reactor and samples were kept in constant temperature bath at 70oC for an hour. The extractive samples were then analyzed by GC/MS. The compounds were identified using GC diagram which shows abundance and retention time of each compound, and calculation of quartz index and Adams table.
Results: The result of GC-MS showed that there exist 68 and 105 compounds in wood of Populus nigra and Populus detoides, respectively. di-Limonene (30.26%), bis (2-ethylhexyl) phthalate (10.07%), Gamma-Sitosterol (1.06%), Hexadecanoic acid (2.0%), gamma-Terpinene (4.02%) and 4-Hydroxy-Benzoic acid (3.62%) were the most important compounds in wood of Populus detoides. There were the Limonene (25.62%), Anymol (5.29%), gamma-Terpinene (3.38%), 1, 2-Benzandicarboxylic acid (2.00%) and bis (2-ethylhexyl) phthalate (0.68%) as the most important compounds in wood of Populus nigra.
Conclusion: The gas chromatographs showed that Limonene, Benzene methanol, alpha-Terpineol, beta-Bisabolene, Hexadecanoic acid and bis (2-ethylhexyl) phthalate were the 7 common compounds in the wood of Populus nigra and Populus deltoides. These compounds can play an important role in the durability and consumption of these woods.
Research Paper
Physics and Mechanical Wood
Ebrahim Khosravi; Amir Lashgari; Mehran Roohnia; Ahmad Jahan latibari; Ajang Tajdini
Abstract
Background and objectives: From the limitations of detecting the amount of useful life remaining in the components of the structures in the conditions of use with acoustic methods is the impossibility of calculating the modulus of elasticity due to the impossibility of removing the part from the structure. ...
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Background and objectives: From the limitations of detecting the amount of useful life remaining in the components of the structures in the conditions of use with acoustic methods is the impossibility of calculating the modulus of elasticity due to the impossibility of removing the part from the structure. Therefore, most of the classifications during use in the components of structures such as historical buildings are based on measuring the speed of sound. In this research, to calculate the local and global density with the method of pin penetration rate in wooden tie in order to calculate the amount of their remaining useful life by combining stress wave and free longitudinal vibration methods has been studied. There was no significant difference between the values of global sound velocity and global modulus of elasticity with the local results of these factors at the five tested points in each of the wooden tie.Methodology: The number of three saturated wooden tie from Iran Railway Company and with the dimensions of 15x25x260 cm, which are made of beech species (Fagus orientalis) and the density was measured by pin penetration method at 5 points of each wooden tie (50 cm distance between each point) and the average results of 5 points were compared with the results of ISO 13910 standard method. The stress wave test was carried out at the same 5 points of density determination by pin penetration rate method to determine the local modulus of elasticity and the results of each point were compared with the global modulus of elasticity of the beam. Longitudinal vibration test was also performed to calculate the damping factor values of the samples.Results: The results showed that there was no significant difference at the 95% level between the values calculated with both the ISO 13910 standard methods and the pin penetration rate method, and there was a favorable linear correlation between the results of the two methods. According to the results, there was no significant difference between the global sound speed of the beams and their local sound speed in any of the five measured points at the 95% level and there was a linear correlation between the values of the global sound speed and each of the five local points. There was no significant difference at the 95% level between the values of the global modulus of elasticity and the values of the local modulus of elasticity calculated in each of the five points. Also, there was a linear correlation between the values of the global modulus of elasticity and the results of the local modulus of elasticity in each of the five points. There was an exponential correlation between the values obtained from the global modulus of elasticity and the damping factor of each of the wooden tie.Conclusion: The equality of density according to the ISO 13910 standard method and the nail penetration method, as well as the equality of the modulus of elasticity calculated by the stress wave method and the free longitudinal vibration method, make it possible to obtain all the data required for calculations without removing the part from the structure. The remaining strength of wooden components should be provided according to EN338 standard.
Research Paper
Composite wood products
Amir Nourbakhsh; Abolfazl Kargarfard; Ali Nourbakhsh; فرداد Golbabaei; Reza Hajihassani; Kamyar Salehi
Abstract
Background and objectives: The possibility of using agricultural lignocellulosic waste as a complementary raw material for the production of wood composite products can have a good economic justification. This will be possible if the manufactured product has the desired and standard quality, however, ...
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Background and objectives: The possibility of using agricultural lignocellulosic waste as a complementary raw material for the production of wood composite products can have a good economic justification. This will be possible if the manufactured product has the desired and standard quality, however, considering that the type of wood material can have a determining effect on the physical and mechanical properties of the final product, therefore, conducting laboratory and research studies in order to recommend A raw material is essential for consumption in industry. The use of agricultural lignocellulosic waste in wood composite products industries has been the subject of various research activities in different parts of the world in recent years. In this research, in order to improve the mechanical and physical properties of wood-plastic, nanoclay particles have been used as reinforcements and corncob wastes have been used with poplar wood.Methodology: The amount of polypropylene and combination of materials were 60 wt% and 40 wt% respectively. The Nano-clay was added in three levels 0, 2 and 4 wt% and the amount of coupling agent was fixed and set to 2 wt% for all treatments. The control samples were made using poly propylene material. Results: The results showed that the tensile and flexural strengths were increased by the addition 25 corncob and 75 poplar wt% particles. For tensile and flexural modulus, adding 2 wt% of nano-clay led to an increase in strength and modulus but there was a decrease when 4 wt% nano-clay was used. The impact strength increased by adding nano-clayConclusion: According to the mechanical and physical properties of all the treatments, the samples which were made of 25 corncob and 75 poplar wt% particle with 2 wt% of Nano-clay had better results compared to other samples.
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