Research Paper
Composite wood products
Abolfazl Kargarfard
Abstract
The potential of cotton stalks residues for the production of particleboard was investigated. Three resin dosage gradients (10% core:10% surface; 9%core:11% surface and 8% core:12% surface) and three press times (3, 4 and 5 minutes) were selected as the variables were produced. Then the mechanical and ...
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The potential of cotton stalks residues for the production of particleboard was investigated. Three resin dosage gradients (10% core:10% surface; 9%core:11% surface and 8% core:12% surface) and three press times (3, 4 and 5 minutes) were selected as the variables were produced. Then the mechanical and physical properties of the boards were measured and statistically analyzed. The results of modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB) measurements showed that as the resin dosage gradient increases, these properties increased and the effect of this variable on these properties was statistically significant. The highest values were reached when either 2 or 4% resin dosage gradients were applied. The effect of resin dosage gradient on thickness swelling after 2 and 24 hours immersion in water was also statistically significant and these properties were improved. The effect of press time on thickness swelling was also statistically significant and the lowest thickness swelling was observed at 5 minutes press time. The results indicated that if 2 or 4% resin dosage gradients and either 4 or 5 minutes press time is applied for the manufacturing of particleboards using cotton stalks residues, the specification of the boards meet the EN specification.
Research Paper
Pulp and paper
Ramin Vaysi; Ali reza Bagheri
Abstract
The objective of this research was accomplished on the effects of total chlorine free (TCF) and elemental chlorine free (ECF) bleaching on optical and mechanical properties of bagasse soda pulps. For this purpose, some unbleached bagasse soda pulps were randomly selected from Ahvaz Pars industry. Then ...
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The objective of this research was accomplished on the effects of total chlorine free (TCF) and elemental chlorine free (ECF) bleaching on optical and mechanical properties of bagasse soda pulps. For this purpose, some unbleached bagasse soda pulps were randomly selected from Ahvaz Pars industry. Then these pulps were bleached with one, two and three P, OP, OPY, O(Ep)P, EHP and O(Ep)H bleaching stages by using oxygen(O) hydrogen peroxide(P), alkali extraction with hydrogen peroxide(Ep), sodium hypochlorite(H) and sodium dithionite(Y). The hand sheets with 70 gr/m2 were prepared from above-mentioned of pulps, and then the optical and mechanical properties were measured and compared according by using TAPPI standard test methods. The results showed that brightness, greenness, tear (except EHP stages), tensile, burst, breaking length strengths and folds were increased and opacity and a* factor were decreased by ECF and TCF bleaching stages. The effects of TCF bleaching stages were more sensible than ECF bleaching stages in improve of bagasse soda properties, too. In general, role of three OPY and O(Ep)H stages and two OP bleaching stages were better than EH(control) stage and unbleached bagasse soda pulps mill in improve of brightness and its paper strengths, too.
Research Paper
Mehrabi Madhoshi; Maliheh Alizadeh
Abstract
In order to establish a kiln drying schedule for Iranian Beech (Fagus orientalis) lumbers of 5.5 cm thickness, commercially cut from Shast Kola region , 5 km distance from Gorgan. They were then dried under the program based on diffusion theory (from Malmquist's relations) were adopted to dry the lumbers ...
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In order to establish a kiln drying schedule for Iranian Beech (Fagus orientalis) lumbers of 5.5 cm thickness, commercially cut from Shast Kola region , 5 km distance from Gorgan. They were then dried under the program based on diffusion theory (from Malmquist's relations) were adopted to dry the lumbers to the final moisture content of 12±2 %. This program for three separate kiln charges and initial moisture content 66.6, 58 and 45 percent was developed. Initial drying bulb temperature (first step) 46 °C and wet-bulb temperature 45 °C was calculated and in three schedules were same. The severity of surface, end checks and warp (bowing, crooking, twisting) in the lumbers were measured before and after the drying process and quality control methods were used to analyze the wood defects. Results indicated that drying of beech lumber using this new schedule was satisfactory. Also intensity changes of defect in all three repeats were about acceptable quality and quantity. Superior characteristics of this program was no surface checks in samples because the moisture content was reduced slowly.
Research Paper
Hossein Jalali Torshizi; Raahil Chaalaakeh
Abstract
Recently, Biorefinery is highly focused as a predominant developer in Forest product industry. Pulping black liquor as a rich residual in biopolymers from plant biomasses, has a great potential in bioenergy and biomaterials. In this study, the effects of surface coating of black liquor from bagasse soda ...
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Recently, Biorefinery is highly focused as a predominant developer in Forest product industry. Pulping black liquor as a rich residual in biopolymers from plant biomasses, has a great potential in bioenergy and biomaterials. In this study, the effects of surface coating of black liquor from bagasse soda pulping (BLBSP) in raw and filtrated form (as 2.5 g. O.D) with different concentration (30, 37, 44 & repeated 44%) on recycled based paper and its properties were investigated. Totally, the BLBSP filtration improved the paper properties more than the raw type, due to its impurity and coarse materials extraction. Higher concentration and content of the applied coatings enhanced grammage (up to 44%) and reduced water absorption (to <30%), constantly, because of mostly hydrophobic material (lignin and minerals) accumulation which would increase the paper mass and would fill the porous structure, resulted in reduction in water adsorption capacity of the lignocellulosic network. But the optimum treatment respect to the tensile, burst and tear strengths was the lowest applied concentration, which are attributed to the easier BLBSP penetration into the paper structure and its contribution in bonding. Recycled paper usage in packaging purposes require compression and bending strengths that increased by the liquor concentrating as bending stiffness (up to >200%) and compressive crush resistance (up to >150%). In this regard, film formation, thickening the paper and also the effective role of lignin could be noted beside the bonding enhancement. Repeatedly application of the BLBSP no significantly improved the almost properties, but also decreased them.
Research Paper
Management and Economics wood
Mysam Khalilian Shalamzari; Mahammad ali Sadat nia; Hamid reza Pirayesh
Abstract
The aim of this study was to investigate the effects of natural weathering induced by critical climate conditions on quality of sugarcane bagasse lignocellulosic material in Pars factory. The experimental samples selected from fresh and also stored bagasse for durations of 6 months, 1, 2 and 5 years, ...
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The aim of this study was to investigate the effects of natural weathering induced by critical climate conditions on quality of sugarcane bagasse lignocellulosic material in Pars factory. The experimental samples selected from fresh and also stored bagasse for durations of 6 months, 1, 2 and 5 years, were used. The mechanical and the chemical properties as well the color variations were measured on taken samples. The results showed that the long storage durations of bagasse significantly decreased the quality of row materials observed in hand sheet tensile and fold strengths. The results illustrated that the amount of Lignin and extractives increased (44 % in lignin and 32% in extractives amount respectively) and also decrease in amount of cellulose and hemicellulose was found (10% for cellulose and 43% for hemicellulose) during 5 years storage in yard. According to the results, there was an obvious difference in L and a color index of 5 years old bagasse in comparing with those of fresh bagasse. Finally it can be drawn that the use of discorded and weathered bagasse could cause the loss in the final products quality which means more chemical treatment for bleaching and more using long fiber in paper making process.
Research Paper
Pulp and paper
zahra takzare; kermanian hossein; omid ramezani; Esmaeil Rasooly Garmaroody; Ali Abdolkhani
Abstract
In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, ...
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In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, and in four times 15, 30, 60 and 90 minutes and rate of liquor to waste 7:1 in Soda process. Obtained Soda pulps were evaluated in yield, lignin percentage, water retention value (WRV), viscosity and crystallinity. Results showed that by prolonging of cooking time, pulp yield and lignin percentage were decreased and WRV increased. Also, pulp viscosity in 30, 45 min was increased by increasing in cooking time that according to other results, it seems that it is false viscosity. In addition, accordance with characterizing of samples by XRD, by progressive cooking time from 15 to 45 min, sample crystallinity decreased and in 60 min its value is increased. According to the pulps viscosity and downward trend of lignin removal with progressive cooking time, this addition can be due to crystallization of hemicellulose like xylan on the crystalline zone of cellulose chain. Therefore, according to the results and based on Bio-refinery concept, cooking time 30 min suggested as the best option for production of high value-added products in saccharification process.
Research Paper
Pulp and paper
Bagher Ashrafi Rad; Mohammad Azadfallah; Fatemeh Kolaei Moakhar; Soheila Izadyar; Mehdi Rahmaninia
Abstract
Utilization of paper as packaging material and developing applied technological program on paper-based substrate are drastically dependent to control of cellulosic fiber hydrophilicity and to enhancement of its hydrophobic properties. Then this work carried out with the aim of developing hydrophobic ...
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Utilization of paper as packaging material and developing applied technological program on paper-based substrate are drastically dependent to control of cellulosic fiber hydrophilicity and to enhancement of its hydrophobic properties. Then this work carried out with the aim of developing hydrophobic surface on cellulosic fiber with layer by layer (LBL) method while keeping and enhancing the properties of paper network. The deposition was implemented by titanium dioxide nanoparticles and poly acrylic acid as cationic and anionic layer respectively on the fibers of unbleached hardwood Kraft pulp and using Zycosil and fluoroalkyl silane on the last layer. The hand-sheets were then made by this modified fiber. The contact angle and roughness were measured to evaluate the effect of layers on hydrophobicity. The results indicated that roughness increased with the number of layers. The instant contact angle was also increased with the number of layers and reached approximately to 110 degree at 7th layer. The dynamic contact angles dropped more lately with increasing the number of layers. The fluorosilane deposition as 8th layer in comparison with Zycosil showed more effect on surface energy reduction. The instant contact angle of Zycosil treated paper was measured 125 degree which dropped significantly to 48 degree after 30 seconds. However, fluorosilane modified paper exhibited contact angle of 140 degree at the same time. In addition, the presence of titanium dioxide nanoparticles on the surface of fiber was demonstrated by scanning electron microscopy (SEM) of paper surface.
Research Paper
Composite wood products
masoudreza habibi; Ahmad Jahan Latibari; Saeed Mahdavi
Abstract
This study was carried out to investigate the effect of storage time and moisture content of bagasse on the physical and mechanical properties of particleboard. For this purpose, wet depitting bagasse was used and samples were maintained in bailing storage method. In this study, was applied 4 storage ...
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This study was carried out to investigate the effect of storage time and moisture content of bagasse on the physical and mechanical properties of particleboard. For this purpose, wet depitting bagasse was used and samples were maintained in bailing storage method. In this study, was applied 4 storage times (1.5, 3, 4.5 and 6 months) and 2 moisture content of Bagasse (45% and 55%). According to these variables, particleboards were made. Also chemical properties (pH, acid and alkaline buffering capacity) of Bagasse were determined. The mechanical and physical properties of the boards were measured and statistically analyzed using factorial experiment and complete randomized design. Then Duncan multiple range test was used for grouping of the averages. The results revealed that with decreasing of Bagasse moisture content, Bagasse sample pH and acid buffering capacity were decreased and increased, respectively. Also bending properties and thickness swelling after 24 hours immersion of the boards were improved. With increasing of storage time, the chemical properties of Bagasse tend to be alkaline, and the minimum of board internal bond strength was obtained in 1.5 month storage time. The physical properties of boards were improved with increasing of storage time
Research Paper
Composite wood products
Mohammad Ahmadi; Bita Moezzipour; mearaj sharari
Abstract
In this study properties of fibers recycled from MDF wastes as one of the potential important resources as raw materials for MDF production were investigated. For this purpose, two different methods including ohmic heating (for 2 and 4 min) and hydrothermal method (at 105˚c for 150 min) were utilized ...
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In this study properties of fibers recycled from MDF wastes as one of the potential important resources as raw materials for MDF production were investigated. For this purpose, two different methods including ohmic heating (for 2 and 4 min) and hydrothermal method (at 105˚c for 150 min) were utilized for recycling the wastes of MDF and original fibers were studied as control sample. The chemical composition of fibers (lignin, cellulose and hemicellulose content), as effective variable on quality of fibers was measured. Also for probing the chemical characteristic of fiber surface, FT-IR test was utilized. In addition, the wettability of fibers also was determined by measuring the contact angels between fibers surface and water drop. The results showed that the chemical composition of fibers is changed within recycling process. Most changes were occurred in hemicellulose and extractives content. The results of FT-IR test revealed the existence of more carbonyl groups and furfural and lower amount of hydroxyl groups in recycled fibers compared to original fibers which caused by esterification process. The wettability of fibers was decreased after recycling process especially in hydrothermal method.
Research Paper
Chemistry of wood
Soheil pourmahmoudi; Iman Torabi vostikulaee; Elham Omidbakhsh Amiri
Abstract
Mazandaran wood and paper industry is known as the largest manufacturer of paper in the Middle East. Black liquor is liquid product of pulp cooking chemical process, which is much polluted because of some organic and inorganic compounds. So, chemical and energy recovery of black liquor are one of the ...
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Mazandaran wood and paper industry is known as the largest manufacturer of paper in the Middle East. Black liquor is liquid product of pulp cooking chemical process, which is much polluted because of some organic and inorganic compounds. So, chemical and energy recovery of black liquor are one of the interesting studies. There are different ways for this one among them concentration method of liquor is used in Mazandaran wood and paper industry. In this work, Condensing unit of liquor was simulated by Hysys software. Then, simulation results were compared with factory data and acceptable results were obtained. In the next step, the effect of operating conditions of the two main feed streams was studied. The results showed that with increasing of dilute liquor temperature, concentration of output liquor flow increases as per 40°C increasing of temperature, almost 28 percent of the condensed value increases. Also, by 10 kPa increasing of the dilute liquor pressure, approximately 39% of condensed value decreases. By increasing the pressure and flow rate of steam, concentration of output liquor somewhat increases, while, this increasing for flow rate, is initially steep and then less steep. The effect of steam temperature on the concentration of output liquor at different pressures must be checked individually.
Research Paper
Composite wood products
Laya Jamalirad; Fereshteh Kor; Farshid Faraji; Sahab Hedjazi
Abstract
In this research, the manufacture of particleboard using lignocellulosic residues including wheat straw and tobacco stalks mixed with industrial wood chips were studied. The variable factors included the mixture of wheat straw and tobacco stalks with industrial wood chips in four levels 0/100, 20/80, ...
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In this research, the manufacture of particleboard using lignocellulosic residues including wheat straw and tobacco stalks mixed with industrial wood chips were studied. The variable factors included the mixture of wheat straw and tobacco stalks with industrial wood chips in four levels 0/100, 20/80, 40/60 and 60/40 (In any combination, according to the desired levels, tobacco stalks and wheat straw were used equally) and the amount of urea formaldehyde resin was at two levels 12 and 14% of the dry weight of the wood chips. The results showed that by increasing the mixture of wheat straw and tobacco stalk up to 60 percent, the physical and mechanical properties of the boards decreased significantly. But increasing the amount of adhesive consumption up to 14 percent had a positive impact on the physical and mechanical properties of the boards and improved internal bonding, bending strength and modulus of elasticity and dimensional stability of the boards. It means that by increasing the use of this type of wastes up to 40 percent with an increase in the amount of UF adhesive up to 14% can be produced the boards with the mechanical properties at standard level.
Research Paper
Pulp and paper
Hossein Resalati; Mostafa Nikkhah Dafchahi
Abstract
Due to shortage of harvestable forest wood in Iran, the potential of CMP pulp production from various species of salix (alba, fragilis and aegyptica), in comparison with populus deltoides, was investigated across this research work. The cooking liqour of Mazandaran wood and paper Mill, consisting of ...
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Due to shortage of harvestable forest wood in Iran, the potential of CMP pulp production from various species of salix (alba, fragilis and aegyptica), in comparison with populus deltoides, was investigated across this research work. The cooking liqour of Mazandaran wood and paper Mill, consisting of 50:50 ratios of sodium sulfite and sodium bisulfite, and hydrogen peroxide, were used for Chemical treatment and bleaching of the pulps, respectively. The results showed that the paper pulps of fragilis salix and alba salix had higher bulk and lower opacity than other species, respectively. From the strength properties point of view, the highest and lowest tensile strength of produced papers were related to alba and fragilis species, and, the highest and lowest burst and tear strength of the prepared papers have belonged to Salix aegyptica and Populus species, respectively. The data have shown that Salix species have a good pothential to be used as raw material to produce CMP pulp at the cooking yield of 85%. According to the results of this research work, alba salix and aegyptica salix are in first and the second priority to produce CMP pulp ,at the cooking yield of 85%, respectively.
Research Paper
PANTEA OMRANI; Hadi maryami; Reza Eisapor
Abstract
Joints in furniture and wooden structures due to the highly sensitive bearing load are today one of the most important scientific topics. The most recent method proposed to build wooden joints in Europe and the United States is a method eco-friendly, without using any type of adhesive substance or connector, ...
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Joints in furniture and wooden structures due to the highly sensitive bearing load are today one of the most important scientific topics. The most recent method proposed to build wooden joints in Europe and the United States is a method eco-friendly, without using any type of adhesive substance or connector, called "wood welding". In the present study, the effect of diameter and dowel surface on the tensile strength of softwood joints (made with dowel) was investigated using two methods: wood welding and glue bonding. Polyvinyl acetate glue (PVA) for bonding, species Fir (Abies alba) for members joint and species Hornbeam (Carpinus betulus) for connector dowels were selected as fixed parameters. The structure of the welded surfaces was analyzed using scanning electron microscopy (SEM). The results of the tensile strength test showed that parameters of diameter and type of dowel surface have a significant effect on the tensile strength of softwood joints in both joint methods.
