Mechanical conversion of wood and wooden fittings
Barat ali Keshtegar; Mehrab Madhoushi; Alimorad Rashidi; mahdi mashkour
Abstract
In this research, the effect of Polyvinyl acetate (PVAc) adhesive reinforced with modified carbon nanofibers (CNF) were studied in three levels (0%, 0.4%, 1.5%) on the strength properties of joints commonly in the furniture industry. Modified carbon nanofibers were used as chemically modified surface ...
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In this research, the effect of Polyvinyl acetate (PVAc) adhesive reinforced with modified carbon nanofibers (CNF) were studied in three levels (0%, 0.4%, 1.5%) on the strength properties of joints commonly in the furniture industry. Modified carbon nanofibers were used as chemically modified surface to improve the dispersion in polymer matrix. The bonding of the test specimens were made using of cut out medium density fiber board (MDF) pieces with desired dimensions and dowel wooden with 6, 8 and 10 mm in diameter, and penetration depth at three levels using polyvinyl acetate adhesive reinforced with modified carbon modified nanofiber. Totally, we have 27 treatments with three replicates. The evaluation of the bending moment capacity of test specimens made with freshly formulated adhesive carried out and the effect of other variables was performed on the joints made under tensile loading at a speed of 3 mm/min. The results showed that increasing the weight percent of carbon nanofibers, the diameter of the wooden dowel and the penetration depth and the moment capacity compared to the control samples was increased by 1.6, 1.5 and 1.3 times, respectively. The 0.4% w/w carbon nanofibers, 10 mm diameter and L3 wooden dowel penetration depth had the greatest effect on the strength of the joints.
Management and Economics wood
Mehrab Madhoushi; Vajihe Mojerian Galogahi; Mohammadreza Masteri Farahani
Abstract
Radiography is a method of non-destructive for evaluating the quality of wood construction machinery in order to detect the defects due to natural degradation. The objective of this study was to investigate the assessment of Poplar (Populus deltoides) and beech (Fagus orientalis) wood defects arising ...
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Radiography is a method of non-destructive for evaluating the quality of wood construction machinery in order to detect the defects due to natural degradation. The objective of this study was to investigate the assessment of Poplar (Populus deltoides) and beech (Fagus orientalis) wood defects arising from the decaying by using x-ray non-destructive method. In this study, for each of species, uncolored (no coating) and colored samples by acid catalyzed lacquers and nitrocellulose lacquers were used. Decay resistance test based on modified ASTM D1413 standard was performed. The decay process was done in the periods of 1, 2 and 3 months with use of Coriolus versicolor fungus at laboratory condition. After each of these periods, for the decay of the samples, x-ray imaging by using an imaging at the lateral, tangential and radial direction was done. Results of weight loss confirmed the presence of decay in the radiographic images. The results showed that after 1, 2 and 3 months of exposure to fungus, fungal degradation leads to weight loss in the painted and unpainted samples. So that, the weight loss caused by decay in beech was less than poplar samples. As well, the weight loss of unpainted was less than painted samples, which was also statistically significant. The x-ray results of unpainted and painted samples at the cross, tangential and radial directions indicate that decay has a more impact on beech in comparison to poplar wood structure. The study as well showed that the protective layer has partly a barrier for decay destruction in these samples.
