Vahid Delnavaz; Ahmad Jahan latibari; Ahmad Mirshokraei; Sead Javad Sepide dam
Abstract
Soda - oxygen pulping of old corrugated container to produce totally chlorine free bleached pulp was investigated. In order to reach the optimum delignification condition; four levels of sodium hydroxide (9, 11, 13, and 15 %), three cooking times (90, 120, and 150 minutes) and two cooking temperatures ...
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Soda - oxygen pulping of old corrugated container to produce totally chlorine free bleached pulp was investigated. In order to reach the optimum delignification condition; four levels of sodium hydroxide (9, 11, 13, and 15 %), three cooking times (90, 120, and 150 minutes) and two cooking temperatures (120, and 150 ºC) at 6 bar oxygen pressure were studied. Yield and kappa number of pulps were measured. Results showed that the pulp obtained applying 9% sodium hydroxide, 150 minute delignification time and 150 ºC delignification temperature which produced the pulp with the yield and kappa number of 72.44% and 24.72 respectively was suitable for further bleaching. Strength of selected pulp including burst strength, tensile strength, and tear strength indices were measured as 2.27 kPa.m2/g, 29.19 Nm/g and 10.24 mN.m2/g respectively. The pulp was bleached applying 3% H2O2 and 2% NaOH to reach the final brightness of 57.97% ISO.
Ali akbar Enayati; Hossein Nazerani hoshmand; Kazem Dost hosseini; Ahmad Jahan latibari; Sohrab Rahimi
Abstract
In order to study the optimum manufacturing conditions of wood sawdust-cement perforated blocks, sawdust of headrige saw was mixed with portland cement type II, and then perforated blocks were molded from this mixture. The mixture ratios of sawdust to cement were selected as 28:72, 35:65 and 42:58, ...
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In order to study the optimum manufacturing conditions of wood sawdust-cement perforated blocks, sawdust of headrige saw was mixed with portland cement type II, and then perforated blocks were molded from this mixture. The mixture ratios of sawdust to cement were selected as 28:72, 35:65 and 42:58, respectively. CaCl2 (Calcium chloride) or MgCl2 (Magnesium chloride) at two levels (3%,5% based on the weight of the cement) were used as additives. The results of physical (thickness swelling after 2 and 24 hours soaking in water) and mechanical (compressive strength) properties of the blocks revealed that varying the sawdust to cement ratio imparted differences in physical and mechanical properties of the blocks. The blocks with sawdust to cement ratio of 42:58 showed the highest compressive strength and blocks with sawdust to cement ratio of 28:72 showed the lowest thickness swelling. It was observed that the type of additive did not impose any significant effect on physical and mechanical properties of blocks. Whereas the effect of MgCl2 level on the properties was significant
Pulp and paper
Ahmad Jahan latibari
Abstract
In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping ...
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In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping temperature were used. After digester yield varied between 64.65 and 71.7% and the total yield after defibration was measured as 54.45% and 62%. Unrefined pulp freeness varied between 708 and 765 ml CSF. Pulps produced applying 10-16% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected from further evaluation. These pulps were refined to about 365 ml CSF in a PFI mill and then handsheets were made for strength evaluation. The apparent density of the handsheets varied between 437-488 kg/m3, tear index between 6.51-7.11 mN.m2/g, and tensile index between 29.2 -30.8 N.m/g. Significant difference at 99% was not observed between the strength of the pulps. Then pulp produced applying 10% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected for bleaching trials. Totally Chlorine Free (TCF) bleaching sequence was used for bleaching the selected pulp. Pulps bleached applying 4% H2O2 and 3.5% NaOH, 3% sodium Silicate, 0.5% MgSO4 and 0.3% DTPA for 2 hours showed the highest brightness of 50.69% compared to 29.2% for unbleached pulp.
Management and Economics wood
Amir Tavakkoli; Ajang Tajdini; Mehran Roohnia; Ahmad Jahan latibari
Abstract
Corrugated board is considered as a valuable community for packaging at both international and domestic markets. Therefore for the development of corrugated board industry in Iran and to understand the variation in demand for this product, it's necessary to identify the consumption ...
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Corrugated board is considered as a valuable community for packaging at both international and domestic markets. Therefore for the development of corrugated board industry in Iran and to understand the variation in demand for this product, it's necessary to identify the consumption and production patterns as well as the most important and effective variables influencing it's status. Then the demand & supply for corrugated board can be forecasted. In this study, the dynamic econometric model has been used to demonstrate simultaneous relationship between supply and demand. Coefficients of the model were estimated using 3sls method with the time series data from 1981 to 2007. The results indicated that in the demand function, intercept, price, GNP in previous period, population, CPI, industrial added value(Iav), production index of large-scale industries(PILSI) and the war dummy variables are significant at 0.05 level. In the supply function, intercept, production quantity in previous period, inflation rate, corrugated board price-raw material price ratio in previous period, import quantity in previous period, cost price all in previous period and subsidy dummy variables are significant at 0.05 level. Results indicate that the mentioned variables influence consumption and production, simultaneously. The results of projection also demonstrate that corrugated board production & consumption will increase into 2012.
Pulp and paper
Mohammad Ahmadi; Mohammad mehdi Faezipoor; Ahmad Jahan latibari; Sahab Hejazi
Abstract
Neutral sulfite semi chemical pulping of Canola residues has been investigated. Canola residues collected from research farm at Agriculture and Natural Resources, University of Tehran, in Karaj. Chemical composition of Canola residues including cellulose, lignin, extractives soluble in ethanol-acetone ...
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Neutral sulfite semi chemical pulping of Canola residues has been investigated. Canola residues collected from research farm at Agriculture and Natural Resources, University of Tehran, in Karaj. Chemical composition of Canola residues including cellulose, lignin, extractives soluble in ethanol-acetone and ash were determined using relevant TAPPI standard test methods. Fiber dimensions of Canola residues were also measured. Then neutral sulfite semi chemical pulps were produced from Canola residues applying following conditions: Cooking time at 3 levels(20,40,60min),chemical charge at 5 levels(8,10,12,14,16 %), Cooking temperature was kept constant for all cooks at 175ċ , Na2SO3 to Na2CO3 ratio was 3:1,and liquor to Canola residues at 8:1. Each pulping was repeated tree times. At the end of each cooking, initial defibration was carried out using a laboratory disc refiner. Total yield before defibration and yield after defibration and screened yield were determined. The highest yield (72%) was obtained at treatment combination of and the lowest yield (58.7%) was in treatment of .Both factors, time and chemical charge, had significant effect on yield and increasing these two factors caused lower yield.
Pulp and paper
Omid Hosseinzadeh; Ahmad Jahan latibari
Abstract
The influence of pulping temperature and time on strength properties of bagasse soda pulp was investigated. Two cooking temperatures)175ْC,185 ْC (and three cooking times (20,30,40 minutes) were selected .The other variables were kept constant at 18 % NaOH and l/w=8. Tensile strength, tear strength ...
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The influence of pulping temperature and time on strength properties of bagasse soda pulp was investigated. Two cooking temperatures)175ْC,185 ْC (and three cooking times (20,30,40 minutes) were selected .The other variables were kept constant at 18 % NaOH and l/w=8. Tensile strength, tear strength index and folding endurance of hand sheets measured . Factorial experiment and randomized block design was used for statistical analysis and DMRT was used for grouping the means. The results indicate that, application of intermediate cooking intensity produced better pulp than more intense pulping at highest pulping time and temperature. However, more intense pulping produced better folding endurance and pulp prepared at 30 minutes cooking time showed better folding endurance than pulp produced at 20 minutes. The highest tear index was obtain at 185 ْC and 20minutes and lowest at 185ْC and 40 minutes. Results indicate that undamaged fibers will product highest tear index. The highest folding endurance was produced at 175 ْC and 30 minutes and the lowest at 185ْC and 30 minutes .Increasing pulping time reduced tensile index and the highest and lowest tensile index obtained at 20 and 40 minutes pulping time respectively.
Mechanical conversion of wood and wooden fittings
amir lashgari; Ahmad Jahan latibari
Abstract
The influence withdrawal strength and bending moment of mortise and tenon joint is investigated. Based on vast application of this type of different length of joint, the effect of tenon lengths (20 , 30, 40, mm) and wood type (beech, alder,spruce) These strength properties is investigated. 9 combination ...
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The influence withdrawal strength and bending moment of mortise and tenon joint is investigated. Based on vast application of this type of different length of joint, the effect of tenon lengths (20 , 30, 40, mm) and wood type (beech, alder,spruce) These strength properties is investigated. 9 combination of variables and total of 72 T-shape samples were tested at loading rate of 1.25 mm/min. The combination of variables significantly in fluences the load bearing capacity of joint. Joint produced with tenon lenghts of 30 mm and alder wood showed highest withdrawal strength and the joint produced at the tenon length and beech wood showed highest bending moment so this combination of variables is recommended.
Composite wood products
Ali Akrami; Kazem ِDossthoseini; Ahmad Jahan latibari; Mohammad mehdi Faezipoor
Abstract
In this investigation, the effect of paraffin content and press time and temperature on practical properties especially surface roughness of particleboard is studied. The variables such as paraffin content at 0, 1& 2 percent, press temperature at 170° and 180° C and press time of 4 and 5 ...
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In this investigation, the effect of paraffin content and press time and temperature on practical properties especially surface roughness of particleboard is studied. The variables such as paraffin content at 0, 1& 2 percent, press temperature at 170° and 180° C and press time of 4 and 5 minutes were investigated.
Modulus of rupture, modulus of elasticity, shear strength, water absorption and thickness swelling after 2& 24 hours soaking in water & surface roughness were measured.
The results indicate that there is no significant difference on the influence of paraffin content on either MOR & MOE of the particleboard. But increasing paraffin content decreased shear strength of panels.
However, addition of paraffin reduced water absorption and thickness swelling.
Press temperature had no significant influence on measured properties, but this variables increased surface roughness. Increasing press time, improved MOE, but showed no significant influence on other properties.
Omid Ramazani; Ahmad Jahan latibari; Mohammad mehdi Faezipoor; Ali akbar Enayati; Sayed mehdi Manzor alajdad
Abstract
Apparent Density of paper is the most effective physical property which directly and indirectly affects most of the strength and optical properties of paper such as tensile strength, modulus of elasticity, light scattering coefficient as well as the bonded area between fibers. Since paper making variables ...
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Apparent Density of paper is the most effective physical property which directly and indirectly affects most of the strength and optical properties of paper such as tensile strength, modulus of elasticity, light scattering coefficient as well as the bonded area between fibers. Since paper making variables influences the apparent density of paper, in this study, the influence of OCC pulp freeness, and drying conditions are investigated. The influence of three freeness levels of 350,450, and 550 CSF, drying under strain and unstrained, drying temperatures of 100, 150, 200 C and drying pressure of 7 and 10 kg/cm2 are studied. The relationship between paper making variables and apparent density is developed. All measurements of apparent density were analyzed using Minitab 15 and regression model between independent variables was calculated. The results showed that both pulp freeness and drying temperature had the highest impact on apparent density and both factors increased the apparent density. The response of apparent density of the hand sheets dried at 200 ◦C varied considerably and was analyzed thoroughly. Higher pressure increased apparent density of the sheets. The combined effect of variables is also considered. The combined effect of pulp freeness and drying temperature caused lignin softening and delamination. However, the influence of increasing the drying pressure for unrefined and less refined pulp is not significant. Furthermore, for unstrained drying, the influence of freeness on apparent density was more than strained drying. Manufacturing of more desirable quality papers would be possible considering the obtained results and the effect of Apparent Density on paper strength properties.
Physics and Mechanical Wood
Habib Nori; Ahmad Jahan latibari; mohammad ghofrani
Abstract
Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon ...
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Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon 44.9, populous deltoids 69.55, and populous euramerican are investigated. The average fiber length of these three colons were 0.854, 1.148, 1.08 mm. respectively and their average dry specific gravity were 0.386, 0461, and 0.341 g/cm3, and also their average cellulose content were 50.5, 51.5, and 49.5 percent.For Kraft process cooking of the mentioned colons, three cooking time, 1, 2, and 3 hours, 17°C cooking heat, 25% sulfidity, and active alkali at 3 levels, 15, 17.5, and 20% were used. The results show that p. alba, colon 44.9, and p. deltoids colon 69.55 with using 20% A.A and 3 hours cooking time have 53% yield and 18 kappa number.
Physics and anatomy
Shamohammad Amiri; Ahmad Jahan latibari
Abstract
For the determined of Anatomical, Chemical and Physical characteristics of SAXAUL wood (Haloxylon persicum) from Haresabad-e-Sabzevar research station located in Khorasan-e- Razavi province 4 trees from this specie were selected and cut. Samples transferred to the Chemical laboratory in Alborz-e-Karaj ...
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For the determined of Anatomical, Chemical and Physical characteristics of SAXAUL wood (Haloxylon persicum) from Haresabad-e-Sabzevar research station located in Khorasan-e- Razavi province 4 trees from this specie were selected and cut. Samples transferred to the Chemical laboratory in Alborz-e-Karaj research center for studies. Anova-1 in mstat-c statistical software was used for statistical analysis. Anatomical characteristics measured Fiber length, Fiber diameter, lemun and cell wall thickness 336.22, 13.61, 3.68 and 4.99 micron, respectively. Paper making coefficients were also measured. Mix up coefficient; Flexibility coefficient and Rankle coefficient were 24.72, %27.05 and %2.71, respectively. Chemical characteristics measured cellulose, lignin, alcol-acetone soluble extractives, NaoH 1% soluble extractives, hot water soluble extractives and ash 46.50%, 29.54%, 7.37%, 16.25%, 6.92% and 1.27%, respectively. Physical characteristics measured of density, dry density and critical density 1024.25, 1003.83 and 913 gr. per cubic centimeter.
Composite wood products
Shamohammad Amiri; Ahmad Jahan latibari
Abstract
The property of MDF obtained the mixture of Haloxylon persicum wood (Saxaul) with Carpinus betulus (Hornbeam) at 100:0, 75:25, 50:50, 0:100 ratios is investigated in this study. The results of this study showed that there is significant statistical differences (1%) among combinations of woods for MOR, ...
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The property of MDF obtained the mixture of Haloxylon persicum wood (Saxaul) with Carpinus betulus (Hornbeam) at 100:0, 75:25, 50:50, 0:100 ratios is investigated in this study. The results of this study showed that there is significant statistical differences (1%) among combinations of woods for MOR, MOE, IB, thickness swelling after 2 & 24 hours and water absorption after 2 & 24 hours. The bending strength (MOR) of MDF produced of Hornbeam wood fibers was highest and Saxaul wood fibers were lowest. Boards produced from 50% Hornbeam and 50% Saxaul, showed the important of bending strength 57%. The average modulus of elasticity (MOE) of MDF showed significant statistical differences (1%). MDF produced from Hornbeam wood fibers had showed highest MOE and Saxaul wood fibers showed lowest MOB. The result of internal bonding (IB) showed that MDF produced from Saxaul wood fibers possessed lowest IB and Hornbeam wood fibers had highest IB. In other two combinations of Hornbeam and Saxaul wood fibers, there are no significant statistical differences (1%) with MDF produced from only of Hornbeam wood fibers.
Composite wood products
Abolfazl Kargarfard; Abdolrahman Hosseinzadeh; Kazem Doosthosseini; Ahmad Jahan latibari; Amir Nourbakhsh
Abstract
In this investigation, experimental boards were produced using beech wood particle, mat moisture content gradient at 0,3 and 6%, two press temperature sat 165and 1850 C and two press times at 3 and 5 minutes. 36 sample boards produced and the physical and mechanical properties of those tested.The results ...
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In this investigation, experimental boards were produced using beech wood particle, mat moisture content gradient at 0,3 and 6%, two press temperature sat 165and 1850 C and two press times at 3 and 5 minutes. 36 sample boards produced and the physical and mechanical properties of those tested.The results indicated that mat moisture content gradient had significantly effected on modified of modulus of elasticity of boards, and with increasing mat moisture content gradient, the MOE of boards increased. Also in 0% mat moisture content gradient, increasing of press time, modulus of rupture and modulus of elasticity decreased. However with increasing mat moisture content gradient, increasing of press time caused of these properties modified.On the other hand an inverse relationship observed between mat moisture content gradient and internal bond of boards that due to of negative effect of increasing of vapor pressure were on resin bond quality in middle layer. But with increasing press time from 3 to 5 minutes, the internal bond of boards increased. The results of thickness swelling measurement indicated that with increasing mat moisture content gradient, the thickness swelling of boards increased. However, when press time increased, the thickness swelling of boards decreased.
Pulp and paper
Mehran Roohnia; Ahmad Jahan latibari; Sayed Zyae Aldin Hosseini
Abstract
In this research, pulping of rinds from sunflower seeds by soda process is studied. Fiber length was 0.89 millimeters and its chemical content, contained 40.5% Cellulose, 30.5% Lignin, 3.33% Ash and 1.93% Extractives. Conditions of Soda process were three different soda consummations of (Chemical charge) ...
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In this research, pulping of rinds from sunflower seeds by soda process is studied. Fiber length was 0.89 millimeters and its chemical content, contained 40.5% Cellulose, 30.5% Lignin, 3.33% Ash and 1.93% Extractives. Conditions of Soda process were three different soda consummations of (Chemical charge) 14%, 16% and 18%. Liquor on rinds ratio, was equal to 6, and period of digestion was 30 minutes. Yield and Kappa number on the best choice of conditions of pulping (165 degree of centigrade temperature and 16% soda consumption) were measured respectively 55.7% and 74.96.Using PFImill, four kinds of pulps with four different free nesses were produced from the proper Pulp and were changed to hand sheets. Study on mechanical strength of hand sheets showed that beating has no effect on tear strength from 30 to 40 SR and it reduces this strength after more beating. Practically, no effect was observed on burst strength and breaking length during beating from 30SR to 60SR. This lignocellulose, agricultural residue is a cheap by-product in Sunflower-oil producer factories. Some of them is as a food for live-stocks and some is burned as a source of energy. Because of this, using rind from sunflower seeds in Paper and other cellulosic industries can be useful.
Physics and anatomy
Ahmad Jahan latibari; Fardad Golbabaei; Mohammad reza Amini
Abstract
Pinus teada, which was planted in Pelembera region, shows promising both in growth rate and adaptability. Even though the fiber geometry of P. teada wood in its native growth region is excellent, but for utilization of this wood in pulping, the knowledge of its technological characteristics especially ...
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Pinus teada, which was planted in Pelembera region, shows promising both in growth rate and adaptability. Even though the fiber geometry of P. teada wood in its native growth region is excellent, but for utilization of this wood in pulping, the knowledge of its technological characteristics especially fiber geometry is required.Two trees of this species were randomly selected from Pelembera forests plantation in Gilan and after felling were cut in smaller bolts and transferred to wood &paper research laboratory, research institute of forests and rangelands. Five cross-sections with the thickness of 15 cm were cut from each tree and the cross-sections were used for selection of samples. Fiber geometry measurement samples were prepared from every five annual rings and from each sample, springwood (early wood) and summer wood (late wood) sample were cut separately. Preparations of fiber geometry samples were according to procedure developed by Franklin (1954) and from each sample the dimension of 30 complete and unbroken trachieds was measured.Trachied length, diameter, cell wall thickness and lumen diameter was measured for different elevation in tree and different growth rings in cross-section.Dimension of 3,00 trachieds were measured totally.Average trachied length, diameter, lumen diameter and cell wall thickness of early wood were measured at 3.65mm, 38.97 mm, 28.94 mm and 3.72 mm respectively. Related values for late wood is as follow: trachied length 3.84mm; diameter, 35.54 /lm; lumen diameter, 22.96 mm; and cell wall thickness, 6.29 mn. Average annual growths were measured at 5.66 mm and late wood percentage at 24.13. Felting, flexibility and runkel coefficients were calculated at 97.96, 73.48, and 26.74 respectively. The result of this study indicates that all measured properties increases with increasing the height of tree and from center (pith) toward outer regions (bark). However all the measured values decreased at highest as well as outer locations.Statistical analysis indicated that the difference in measured properties at different heights of trees from center to the bark is significantly different at 1% level.
Amir Nourbakhsh; Bohuslav V.Kokta; Abdolrahman Hosseinzadeh; Ahmad Jahan latibari; Abolfazl Kargarfard
Abstract
This study investigates the effect of maleic anhydride polypropylene (MAPP) addition as a coupling agent at four levels and also the type of cellulosic materials as a reinforcing component on processing and mechanical properties of modified Populus deltoides fiber and flour/ polypropylene composites.The ...
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This study investigates the effect of maleic anhydride polypropylene (MAPP) addition as a coupling agent at four levels and also the type of cellulosic materials as a reinforcing component on processing and mechanical properties of modified Populus deltoides fiber and flour/ polypropylene composites.The results indicate that the interfacial bond between reinforcing-fiber/ flour and the matrix show great influence on the mechanical properties of composites. Furthermore it has been demonstrated that the addition of coupling agent during processing significantly improves the mechanical properties of fiber/ flour polypropylene composites. The results of this investigation indicates that the highest the mechanical properties of composites are as follow; The mechanical properties of the poplar fiber with 2% MAPP is higher than poplar flour without MAPP, which proves that the addition of functional group C=O acts as a good bonding agent. The notched Impact Izod strength value of poplar fiber with 2% MAPP is less than pure PP. But it is higher than other treatments. The results indicate that the interfacial bond between reinforcing fibers and flour with polymer matrix modified MAPP play a significant role in improving the measured mechanical properties of the composites.
Physics and anatomy
masoudreza habibi; Abdolrahman Hosseinzadeh; Ahmad Jahan latibari; Hossein Familian; Hossein Hosseinkhani
Abstract
In this study, annual growth, bark content, fiher dimensions of pine wood (P. eldarica) were measured. Annual ring thickness and bark content 4.95 mm, 12.15% are determined respectively. Fiber length, fiber diameter, lumen cell diameter, cell wall thickness were determined 2.26 mm, 39.63m 29.06 m and ...
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In this study, annual growth, bark content, fiher dimensions of pine wood (P. eldarica) were measured. Annual ring thickness and bark content 4.95 mm, 12.15% are determined respectively. Fiber length, fiber diameter, lumen cell diameter, cell wall thickness were determined 2.26 mm, 39.63m 29.06 m and 5.28 m respectively. Also felting coefficient 58.59, tear coefficient 36.24% and flexibility coefficient 18.12%were measured. Trend of variations of fibers dimensions indicated that fibers longth increased with increasing tree height from butt to crown. Also this property increased from pith to tenth annuad ring then decreased toward of bark. Cell wall thickness decreased from butt to 2 m. height and then increased. Also cell wall thickness decreased from pith toward bark.
Composite wood products
Amir Nourbakhsh; Abdolrahman Hosseinzadeh; Ahmad Jahan latibari; Fardad Golbabaei; Abolfazl Kargarfard; Hossein Hosseinkhani
Abstract
In this experiment the optimum condition of particleboard uom Date palm residues and prosopis (Mesquite) produced in southern part of Iran was investigated. Variable factors as type of raw-material (Date palm and prosopis), resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) and ...
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In this experiment the optimum condition of particleboard uom Date palm residues and prosopis (Mesquite) produced in southern part of Iran was investigated. Variable factors as type of raw-material (Date palm and prosopis), resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) and total of 18 combinations of variables were investigated.Other factors such as type of resin (UF), hardner content (2 percent) type of hardner (NH4CI)press closing time (4.5 mm/sec.), board density (0.7gr/cm3) press pressure (30 kg/cm2) and press temperature (160 C) were held constant.All boards were tested according to DIN-68763 standard. The factorial experimental design at completely random blocks test was used. The results of this study could be summarized as follows: Increasing the resin content from 9 to 11 percent increased MOR, MOE and ID and decreased thickness swelling after two and 24 hours immersion in water.The highest internal bond (IB) was related to prosopis (Mesquite) boards made at 5 minute, prass time. As far as production of date plam and prosopis (Mesquite) wood is concerned, the results revealed that the polymerization of resin and wood is better at 11 percent resin content and 5 minutes of press time. Date palm residues are important with treatment process according to reference. NO. One. Shape and dimension of chipped and flaked particles of date palm residues are important, because type and characteristics of species are different, in the mean time, as date palm residues has very high bulk density and specific surfaces than prosopis (Mesquite) which it has inverse effect on both physical and mechanical properties, thus it should be considered during the process of particleboards production.
Composite wood products
Ahmad Jahan latibari; Habibalah Arabtabar; Fardad Golbabaei; Abolfazl Kargarfard; Amir Nourbakhsh; Abbas Fakhryan roghani
Abstract
Laminated beam ( LB.) and laminated veneer lumber ( LVL) manufactured from maple, hornbeam and beech wood is investigated. Three levels of press pressures at 30, 35, 40 kg/cm2, three levels of layer thicknesses of 2, 3, 4 mm and tangential and radial layers are investigated. Bending strength (MOR and ...
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Laminated beam ( LB.) and laminated veneer lumber ( LVL) manufactured from maple, hornbeam and beech wood is investigated. Three levels of press pressures at 30, 35, 40 kg/cm2, three levels of layer thicknesses of 2, 3, 4 mm and tangential and radial layers are investigated. Bending strength (MOR and MOE) and shear strength were measured according to ASTM 1186 and 905 respectively.The results of this investigation indicated that laminated wood strength of samples produced from hornbeam layers is superior to beech and beech is superior to maple. Statistical analysis of the results showed that the effect of wood species on strength properties is significantly different at 99% level. Press pressure also showed significant effect on strength. Increasing press pressure improved bending properties, but the highest shear strength was observed at 30 kg/cm2. Cutting direction did not influence bending strength and only influenced the shear strength. Even though the initial anticipation was the fact that thinner layer will produce stronger laminated wood. But the results or this study showed that layer thickness did not significantly affect strength properties.
Pulp and paper
Kamyar Salehi; Ahmad Jahan latibari; Abdolrahman Hosseinzadeh
Abstract
In order to investigate the possibility of utilizing bagasse in high yield pulping, CMP and CTMP pulp from bagasse was compared.APMP pulping process was also investigated. Bagasse fiber length, diameter, lumen diameter and cell wall thickness was measured at 1166mm, 19.63 mLm,7.47 mLm, and ...
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In order to investigate the possibility of utilizing bagasse in high yield pulping, CMP and CTMP pulp from bagasse was compared.APMP pulping process was also investigated. Bagasse fiber length, diameter, lumen diameter and cell wall thickness was measured at 1166mm, 19.63 mLm,7.47 mLm, and 6.09 mLm respectively. Chemical composition was as follow: cellulose 553 %, lignin 20.5 %, ash 1.98% and extractive 2.9 %.The results and comparison of CMP and CTMP pulp are as follow: CTMP pulp yield was 3-4% higher than CMP pulp and the highest CTMP pulp at 80.7% was obtained at 15% NaOH application and 15 minutes chemical treatment time.Breaking length of both pulp was almost equal, but the burst index of CMP pulp was higher and the tear index was lower than CTMP. The highest breaking length of 3.85Kmwas obtained at 15% NaOH and 10 minutes, highest burst index of 4.81 KPa.m2/grat 20% NaOH and 20 minutes and highest tear index at 6.87 mN.m2/grat 15% NaOH and 15 minutes treatment time. Various treatments in APMP pulping reveald the following results: - Two stage pulping yield was almost 6% higher than one stage pulping and addition of H2O2 did not significant improve the yield.- The highest breaking length was related and two stage pulping. But addition of H2O2 in last stage and the lowest breaking length was related and two stage pulping with split application both NaOH and H202.- Even though two stage pulping with the addition of H2O2 in one stage produced highest burst index, but lowest burst index was with the CMP pulps.- Addition of DTPA produced highest brightness and opacity.
Fardad Golbabaei; Ahmad Jahan latibari; Abdolrahman Hosseinzadeh; Sayed Javad Sepidehdam; Amir Nourbakhsh
Abstract
Kraft pulping of Pinus eldarica wood was carried out at 18% active alkali, 25% sulphidity and pulping temperature & Time of 165 C and 90 minutes pulp was compared with imported unbleached long fibre pulp with the kappa number of 34. Pinus eldarica pulp (500 ml csf) and imported long fibre pulp 120 ...
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Kraft pulping of Pinus eldarica wood was carried out at 18% active alkali, 25% sulphidity and pulping temperature & Time of 165 C and 90 minutes pulp was compared with imported unbleached long fibre pulp with the kappa number of 34. Pinus eldarica pulp (500 ml csf) and imported long fibre pulp 120 g/m2 hand sheets were prepared for testing. Blending ratios were kept at 5, 10, 15 and 20% for both long fibre pulps.
Upon mixing 5, 10, 15, 20% Pinus eldarica pulp with hardwood pulp, breaking length increased to 6.9, 7.77, 8.01 and 9.14 Km. Respectively, and corresponding figures for imported pulp addition were 6.71, 8.2, 8.25 and 9.27 Km respectively. Tear index is also measured. Adding 5, 10, 15, 20% Pinus eldarica pulp to local hardwood pulp produced tear indexes of 5.93, 6.95, 6.65, 7.08 mNm2/g respectively and corresponding figures for imported pulp 5.38, 5.61 and 5.60 kPa. m2/g with blending above percentages of P. eldarica pulp and 4.78, 5.27, 5.38 and 6.23 kPa. m²/g upon addition of imported pulp.
Saeid Javad Sepideh dam; Ahmad Jahan latibari; Abdolrahman Hosseinzadeh; Fardad Golbabaei
Abas Fakhryan; Ahmad Jahan latibari; Abdolrahman Hosseinzadeh; Fardad Golbabaei; Saeid Mahdavi
Saeid Mahdavi; Abdolrahman Hosseinzadeh; Ahmad Jahan latibari; Hossein Resalati; Abbas Fakhryan roghani
masoudreza habibi; Ahmad Jahan latibari; Abdolrahman Hosseinzadeh; Mohammad mehdi Faezi poor
