Farhad Zeinaly; Ali Kazemi Tabrizi; Amirhosein Jafari Mofidabadi
Abstract
Growing industrial trees is one of the solutions to overcome the wood resources lack. Thus, for efficient investment in wood cultivation, some cases such as annual growth of cultivated species, species adaptation to the climate of the region, adaptation to the soil of the culture site and also the quality ...
Read More
Growing industrial trees is one of the solutions to overcome the wood resources lack. Thus, for efficient investment in wood cultivation, some cases such as annual growth of cultivated species, species adaptation to the climate of the region, adaptation to the soil of the culture site and also the quality of the produced wood and its capability as a raw material used in lignocellulosic industries, must be regarded. One of the recently introduced extremely fast growing poplar cultivars is the “Mofid” hybrid poplar (Populus euphratica Oliv. × P. alba L.). Since the wood and wood-waste produced during the wood mechanical conversion, are used as the main source in the wood-plastic composite production, in this study, the use of 4-year-old Mofid” hybrid poplar wood-flour as filler in the polyethylene wood-plastic production was investigated. Results indicated that the composites with Mofid poplar lignocellulosic filler had acceptable mechanical and physical properties, in a way that they were comparable with the composites containing hardwoods wood-flour filler (control treatment). Results showed that the plasticity and irreversible-strain during applying force were less in poplar filler-composites, so the tensile and flexural moduli were higher than control composites. Results indicated that the use of poplar wood-flour reduced the impact resistance value. Also, among the treatments of 20, 30 and 40% filler, the 30% filler treatment had the highest mechanical properties. All samples had acceptable water-absorption and thickness-swelling characteristics.
Pulp and paper
Farhad Zeinaly; Ali Kazemi Tabrizi; yashar Einollahi; Faraz Asadi Malek Jahan
Abstract
The first act to ameliorate bleaching process is the major elimination of lignin. Actually, the use of oxygen delignification stage before bleaching process is the essential stage in improving bleaching process and reducing process emission. In this study, the effect of conducting oxygen-delignifying ...
Read More
The first act to ameliorate bleaching process is the major elimination of lignin. Actually, the use of oxygen delignification stage before bleaching process is the essential stage in improving bleaching process and reducing process emission. In this study, the effect of conducting oxygen-delignifying process under different process condition, on chemical, physical, mechanical and optical properties of kenaf bast kraft pulp was investigated. The kenaf bast kraft pulp with the kappa number of 22, 1154 ml/g viscosity, and 38% ISO brightness was prepared. Oxygen-delignifying treatments were carried out with three different temperatures of 90, 100 and 110°C, and two oxygen pressures of 5 and 7 bars, with and without magnesium sulfate addition. Results indicated that oxygen delignification treatment led to intense decrease in pulp kappa number, while the pulp viscosity did not change significantly. Results of measuring delignified pulp viscosity showed that the magnesium sulfate addition caused to prevention of pulp viscosity downfall. The increase in reaction temperature had a significant effect on the process improvement, but raising the oxygen pressure did not have a meaningful effect on the process. Also, the pulp brightness was increased about 7%.
Pulp and paper
Farhad Zeinaly; Ahmad Reza Saraeian; Mohammadhadi Aryaei monfared; Ali Kazemi Tabrizi
Abstract
In conducting environmentally friendly processes for pulp production, first step is to reduce the effluent pollution load in each stage, and because the bleaching process is the most polluting stage in the production of pulp, improving it is one of the most important matters. The first act to ameliorate ...
Read More
In conducting environmentally friendly processes for pulp production, first step is to reduce the effluent pollution load in each stage, and because the bleaching process is the most polluting stage in the production of pulp, improving it is one of the most important matters. The first act to ameliorate bleaching process of chemical pulps is the reduction of colored materials, mostly lignin, which enter to the bleaching section. Thus, the use of oxygen delignification stage after pulping and before bleaching process is the key stage in improving process and cleaner production. In this study, the effect of conducting oxygen-delignifying treatment by two kinds of machines, and under different process condition, on chemical, physical, mechanical and optical properties of bagasse soda pulp was investigated. The bagasse soda pulp with the kappa number of 20, 955 ml/g viscosity, and 37% ISO brightness was prepared from Pars Hafttapeh Company. Oxygen-delignifying treatments were carried out with three different temperatures of 90, 100 and 110°C, and two oxygen pressures of 5 and 7 bars, with and without magnesium sulfate addition, by two kinds of machines. Results indicated that oxygen delignification treatment led to intense decrease in pulp kappa number, while the pulp viscosity did not change. Results of measuring delignified pulp viscosity showed that the magnesium sulfate addition caused to prevention of pulp viscosity downfall. The increase in reaction temperature had a significant effect on the process improvement, but raising the oxygen pressure did not have a meaningful effect on the process. The pulp brightness was increased about 4-6%. And also, due to the need of shorter time in order to reach the reaction temperature in the Iranian made machine, pulp delignifying by this machine was a little lower than Quantum machine.
Physics and anatomy
Jalal Shakhes; Ahmad reza Saraeyan; Farhad Zynali
Abstract
This work investigated effect of height and cultivar on morphological properties of bast and core fiber of tobacco stalk (Nicotiana tabacum). Also, in this research cultivar effect on chemical properties of tobacco stalk were investigated. Selected cultivars include Barley and Virginia, and investigative ...
Read More
This work investigated effect of height and cultivar on morphological properties of bast and core fiber of tobacco stalk (Nicotiana tabacum). Also, in this research cultivar effect on chemical properties of tobacco stalk were investigated. Selected cultivars include Barley and Virginia, and investigative height positions were chosen 5, 50 and 75% of stalk height. Results indicated that bast fiber length, diameter and wall thickness are more effective than those of core fiber. Chemical analysis of stalk’s parts indicated that cellulose and ash contents of bast were higher than those of core, but lignin content of bast was significantly less than that of core. Also, extractive material of bast was less. Statistic results showed that length and wall thickness of Barley’s bast fiber were higher compare to Virginia, but there was no significant difference in terms of morphological properties of core fibers between these cultivars. Cellulose percentage of Barley cultivar was higher, where as lignin, extractives and ash contents of Barley were lower than that of Virginia cultivar. Also, cultivar type didn’t have significant effect on contents of tobacco stalk parts (bast, core and pith). Results indicated that, fiber length, diameter and wall thickness of bast decreased as height increases, but in core fiber, just fiber length decreased and other properties of core fiber had different behavior. Moreover, bast and pith percentages increased by height increasing while, core percentage decreased. In general, results of this research showed that, tobacco stalk are a suitable row material for pulp and paper production, re fiber dimensions and chemical components.
