Ali Khaki; َAli Akbar Yazdi Mymand; Mjtaba MirHoseini Taba; Saleh Gohari
Abstract
The increasing demand for durable and lightweight raw materials in home and office furniture makes it necessary to investigate and optimize their properties. In this study, the effect of the sheet type, layout, and thickness were investigated on the mechanical properties of lightweight sandwich panels. ...
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The increasing demand for durable and lightweight raw materials in home and office furniture makes it necessary to investigate and optimize their properties. In this study, the effect of the sheet type, layout, and thickness were investigated on the mechanical properties of lightweight sandwich panels. Two types of sheets were used for making sandwich panels; medium density fiberboards and particle boards with a thickness of 8 mm and cores made of tube (bobbins) cardboard with heights of 30 and 50 mm, in three types of layouts. Urea formaldehyde glue was selected. The bending stiffness and modulus of elasticity were evaluated according to ASTM C 393 and impact strength according to DIN 5218 1992. The results showed that the thickness of the core had a significant effect on the mechanical properties, so that with increasing the thickness of the core, bending stiffness and modulus of elasticity decrease, but impact strength increases. The best results came from specimens made with a 30mm thick, medium density fiberboard core and a Type A layout.
Physics and Mechanical Wood
Fardad Golbabaei; Hossein Hosseinkhani; Amir Nourbakhsh; Abolfazl Kargarfard; Abas Fakhryan
Abstract
Most industrial production processes need cooling water to operate efficiently and safely. Refineries، steel mills، petrochemical manufacturing plants، electric utilities and paper mills all rely heavily on equipment or processes that require efficient temperature control. Cooling water system control ...
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Most industrial production processes need cooling water to operate efficiently and safely. Refineries، steel mills، petrochemical manufacturing plants، electric utilities and paper mills all rely heavily on equipment or processes that require efficient temperature control. Cooling water system control these temperatures by transferring heat from hot process fluids into cooling water. As this happens، the cooling water itself gets hot before it can be used again it must either be cooled or replaced by a fresh supply of cold water. The aim of this study was utilizing domestic wood in cooling towers structure. For this purpose، five wood spices included: Hornbeam، Oak، Alder،Populus and Tehran pine (Eldarica pine) and also five different regions with different climate، included: electric plant Montazer ghaem from Karaj near of Tehran، electric plant Loshan from north of Iran، electric plant Dorcheh Esfahan from center of Iran and petrochemical manufacturing plants Bandar emam from south of Iran، have been chosen. Sampling have been done and treated with CCA. All samples were put in the cooling towers and were tested during the study period. (Mechanical tests such as specific gravity، static bending، compression parallel to grain and hardness). Based on this study، the mechanical properties of these spices during last four years were done. At the fifth year of study، virtual damages have not seen where as significant difference have been achieved in aspect of mechanical properties. Among of theses wood spices، Populous and Pinus eldarica had minimum mechanical degrade and it should be noted that Pinus eldarica spices had better quality than populous spices.
Composite wood products
ghasem asadpour; seyyed majid zabihzadeh; Maryam Ghorbani; mahmoud davoudi
Abstract
Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, ...
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Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, 30 and 40%. Test samples prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. According to the results, bark flour increased water absorption, tensile and bending modulus. High proportion of bark fillers declined mechanical strength. Thermal modification significantly improved physical and mechanical properties of composite. Using lignocellulosic material flour bark hornbeam, tensile modulus and flexural modulus of composite material background had the highest improvement. In comparison between mechanical properties, impact resistance by adding flour bark had the greatest decrease. Thermal modification by increasing the crystallity, hemicellulose degradation, loss of polarity, increased compatibility between the two phases and uniform distribution of bark fillers in polymers, increased mechanical resistance.
Pulp and paper
masoumeh mollaei; Mohammad Azadfallah; Yahya Hamzeh; faramarz khodaian chegini
Abstract
The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. ...
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The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. Therefore to evaluate coatings effects on barrier properties, water vapor transmission rate (WVTR), water absorbance, air resistance and grease proof of coated papers were determined. Moreover, mechanical strength including tensile strength and burst strength were measured. According to the results, the barrier properties and mechanical strength of coated papers improved dramatically than uncoated ones. The best results in WVTR and mechanical strength tests were obtained for coatings with the same ratio of polymers. On the other hand, coating with 75%chitosan - 25% poly (vinyl alcohol) composition exhibited excellent resistance against the grease penetration and water absorption.Keywords: Coating, chitosan, poly (vinyl alcohol), barrier properties, mechanical strength
Fardad Golbabaei; Hossein Hosseinkhani; Abolfazl Kargarfard; Amir Nourbakhsh; Reza Hajihassani
Abstract
The major engineering properties of Pinus taeda L. wood growing in different regions of Caspian forests (North of Iran) was determined. Test materials were selected randomly from Pinus teada tree plantation and the test specimens were prepared according to ASTM D-143 standard. Mechanical and physical ...
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The major engineering properties of Pinus taeda L. wood growing in different regions of Caspian forests (North of Iran) was determined. Test materials were selected randomly from Pinus teada tree plantation and the test specimens were prepared according to ASTM D-143 standard. Mechanical and physical properties were measured on both green and air-dried samples (12% moisture content). The results of the measurement were statistically analyzed based on randomized block design and factorial experiment. The influence of specimen locations at different stem heights was examined. Based on the results of this study, statistically significant difference of the measured properties was not observed between the samples collected from different regions. Toughness was not influenced by moisture content, but the compression strength perpendicular to the grain of wet and air-dry specimens was not similar. Mechanical properties of Pinus teada wood grown in Iran is generally of lower quality compare to those in their original habitat.
Physics and Mechanical Wood
Zoghali Syahipoor; Fardad Golbabaei
Abstract
In this study, in order to achieve sufficient accuracy both quality and quantity factors in two forestry plantanation of Picea abies using 100% statistics were used. In order to investigate wood quality, fiber length, density and mechanical properties, 4 thick cross section trees were selected and cut ...
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In this study, in order to achieve sufficient accuracy both quality and quantity factors in two forestry plantanation of Picea abies using 100% statistics were used. In order to investigate wood quality, fiber length, density and mechanical properties, 4 thick cross section trees were selected and cut in two area of Piseson at high 1450m. altitude and Syahkal at 650m. altitude. According to the results of measuring of diameter, height and average annual growth of the samples and comparison of different sites condition, it could be concluded that plantation of Picea abies is advantageous. Finally, the results show that in Piseson wood with low mechanical properties were produced. The average annual growth of wood in Piseson is 63mm. where as in syahkal is 60mm.
