Composite wood products
Hossein Rangavar; Abolfazl Kargarfard; Mohammad saleh Hosseini fard
Abstract
In this study, the effect of type II and III Portland cement and the use of undepithed and depithed sunflower stalks particles (Helianthus Annuus) with percentages of different mixing ratio of the poplar wood particles (Populous alba) with 100:0, 75:25, 50:50, 25:75 and 0:100 respectively in the manufacturing ...
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In this study, the effect of type II and III Portland cement and the use of undepithed and depithed sunflower stalks particles (Helianthus Annuus) with percentages of different mixing ratio of the poplar wood particles (Populous alba) with 100:0, 75:25, 50:50, 25:75 and 0:100 respectively in the manufacturing of wood-cement composites were studied. Physical and mechanical properties of boards were measured as the effect of lignocellulosic material (sunflower stalks andpoplar wood) and Portland cement type (II and III) on the cement setting time. The results of the study showed that the lignocellulosic material reduced the hydration reaction and increased cement setting time. In this regard, sunflower stalks particles in comparison with poplar wood particles increased cement setting time intensively. The boards made from type III Portland cement had better mechanical strength and physical properties (water absorption and thickness swelling reduced) than with type II Portland cement. In comparison with poplar wood particles usage, the use of sunflower stalks particles and more amount of it caused to mechanical properties decreases and increased the water absorption and thickness swelling after 2 and 24 h water immersion. Therefore the best characteristics were obtained in boards made from 100 percent poplar wood particles. In other hands, using depithed sunflower stalks particles caused to improved the physical and mechanical characteristics. In general, it can be concluded that 25 percent of depithed sunflower stalks particles relative to poplar wood particles (relative to mass lignocellulosic materials( with type III Portland cement in the manufactured wood-cement boards has suitable physical and mechanical properties for usage of these boards in interior building applications.
Management and Economics wood
Mohammad Saleh Hosseini Fard; Saeed Khojasteh Khosro; Behbod Mohebby
Abstract
In this research the effect of oil-heat treatment of Fir species (Abies spp) on contact angle and adhesion strength of organic solvent based and water based coating (acid catalyzed and acrylic water based coating) were investigated. Soy oil was used for the heat treatment modification. Modification process ...
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In this research the effect of oil-heat treatment of Fir species (Abies spp) on contact angle and adhesion strength of organic solvent based and water based coating (acid catalyzed and acrylic water based coating) were investigated. Soy oil was used for the heat treatment modification. Modification process of samples were done at two time, 12 and 15 hours with temperature of 180°C. Control and modified samples were covered with acid catalyzed and acrylic water based coating. Contact angle of water was measured before and after treatment. Adhesion strength of coating was determined according to ASTM 4541 standard. Obtained results of contact angle and adhesion strength were compared with the control samples. The results showed that modification process of oil-heat treatment increased contact angle. This increase continued by increasing treatment time. Increasing contact angle reduced wettability of samples’ surface. On the other hand oil-heat treatment of wood, decreased adhesion strength of coating. The lowest value of adhesion strength was observed in the modification process of 15 hours. Results of comparing coating revealed that acid catalyzed coating had higher adhesion strength than acrylic water based coating but generally no significant differences was observed between these coating.
