Research Paper
Pulp and paper
Amir mohsen Nazry; Mohammad Talaeipoor; Saeed Mahdavi
Abstract
The effects of different fines with different shape and size of mechanical Pulp on Paper Properties in two fractions was investigated. Fines was classified in two categories including fibrils and flakes , and then effect of these particles on pulp properties was studied.The fibril fraction was consist ...
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The effects of different fines with different shape and size of mechanical Pulp on Paper Properties in two fractions was investigated. Fines was classified in two categories including fibrils and flakes , and then effect of these particles on pulp properties was studied.The fibril fraction was consist of fibrillar material, i.e., ribbons, fibrils, and thin lamella particles. The flake fraction consist of flake like material i.e., fiber wall fragments and thick lamella. An advanced image analysis method was used to characterize the properties of fibrils and flakes. The results indicate that the fibrils and flake fractions have distinct characteristics and effect on sheet properties. The fibrils strongly affected the strength properties, while the flakes improved light scattering. Generally, the smaller size Particles afforded higher sheet density and strength. Fines content and fibrillar material are very important parameters in mechanical pulping and can also affect quality controlling of mechanical pulp and papermaking.
Research Paper
Pulp and paper
Maryam Rostaei; Rabi Behroz; Saeid Mahdavi
Abstract
This research was performed to improve the properties of the pulp made of Aspen Deltoides, using antraquinone(AQ) catalizer. Neutral sulfite semichemical (NSSC) method in three efficiency levels of 55, 60, and 65% was applied. Cooking situations was selected as: Specific Temperature (175˚ C) , Time ...
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This research was performed to improve the properties of the pulp made of Aspen Deltoides, using antraquinone(AQ) catalizer. Neutral sulfite semichemical (NSSC) method in three efficiency levels of 55, 60, and 65% was applied. Cooking situations was selected as: Specific Temperature (175˚ C) , Time (Variable) , Specific Percentage of Chemicals 14% and Anthraquinone 0.1% . In all stages of cooking, weight ratio of sodium sulfide to sodium bicarbonate was set as 4.5/1. The ratio of cooking liquid to chips was 5/1. The results indicated that AQ causes an increase in efficiency and a significant decrease in Kappa. Researches also indicated that by the use of AQ, strength indexes of the paper such as strength of burst, tearing, tensile, Ring Crush Test and Corrugating Medium Test increases. Optical experiments on hand sheets following addition of AQ, indicated increase in brightness and decrease in opacity.
Research Paper
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.
Research Paper
Pulp and paper
Somayeh Solimani; Sayed javad Sepidehdam; Hamid Malkian
Abstract
The stability of colored paper through dyes is very important in manuscript restoration. In this project Japanese papers (model papers) were colored with different dyes such as henna, walnut and tea. Artificial aging test was performed on these papers as well. Dye effect on stability of colored papers ...
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The stability of colored paper through dyes is very important in manuscript restoration. In this project Japanese papers (model papers) were colored with different dyes such as henna, walnut and tea. Artificial aging test was performed on these papers as well. Dye effect on stability of colored papers was measured through mechanical (folding endurance, tensile breaking and tear resistance) tests before/after aging test statistically; folding endurance test results in color level is significant. Tea colored paper sample was not as stable as model paper in folding resistance and the average of tea sample compare to model sample was 39.9 to 69.5. Folding endurance reduction was seen in tea and henna samples following aging test. The effects on tensile and tear resistance were not statistically different or dyes were not affected to cause any increase or decrease in stabilities. Scanning electron microscopy (SEM) images of model and dyed papers have demonstrated color and aging effects. The pH test upon henna sample, have shown acidic condition. Model paper was not the same as dyed papers in terms of weight and thickness. All samples include model and dyed papers, demonstrated decrease in brightness and yellowness and increase in redness following aging test.
Research Paper
Composite wood products
Abolfazl Kargarfard; Reza Hajihassani; Fatemeh Rezaei
Abstract
In this investigation, 36 laboratory Medium Density Fiberboard (MDF) panels were produced using beech wood fibers. Variables were three steaming time (5, 10 and 15 minutes), two press time (4 and 6 minutes) and two resin consumption levels (9 and 11%). The physical and mechanical properties of panels ...
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In this investigation, 36 laboratory Medium Density Fiberboard (MDF) panels were produced using beech wood fibers. Variables were three steaming time (5, 10 and 15 minutes), two press time (4 and 6 minutes) and two resin consumption levels (9 and 11%). The physical and mechanical properties of panels were measured and analyzed. The results indicated that the favorite MOR was observed in panels produced through 4 minutes press time, 11% resin consumption and 10 minutes steaming time. Also increase in steaming time to 15 minutes and press time to 6 minutes, caused the MOR and MOE of boards reduced to minimum level. The internal bonding (IB) of boards decreased with steaming and press time increase. However, the panels produced at 25 minutes of steaming time showed minimum of thickness swelling. The results of this investigation indicated that the thickness swelling of boards improved with increase in steaming time. However mechanical properties of boards were higher where the shorter steaming time applied.
Research Paper
Composite wood products
Hamid Hatefnia; Ali akbar Enayati; Kazem Dost hosseini; Mohammad Azadfallah
Abstract
Poplar wood chips were treated by steaming in different conditions. The chemical composition changes of milled wood were studied. The obtained results indicate hemicelluloses degradation, reduction of acetyl groups and formation of organic acid during the treatment. It was also found that steam treatment ...
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Poplar wood chips were treated by steaming in different conditions. The chemical composition changes of milled wood were studied. The obtained results indicate hemicelluloses degradation, reduction of acetyl groups and formation of organic acid during the treatment. It was also found that steam treatment has led to degradation of low-molecular lignin units, decrease in cellulose amorphous regions, increase of acetone extractives and hot water solubility as well as one percent sodium hydroxide solubility. The FT-IR spectra indicated a structural change of aromatic polymers in the wood, cleavage of the acetyl group of hemicelluloses and formation of organic acid.
Research Paper
Composite wood products
Sayed mohammad javad Mosavi hosseini; Mohammad mehdi Faezipoor; Hossein Usefi
Abstract
The effect of using nanoclay on MDF properties was investigated. Sodium montmorolonit (NA+MMT) was used in three levels of 0, 3 and 6 percent based on dry weight of two resins of urea formaldehyde (UF) and Methylene diphenyl diisocyanate (MDI). Modulus of rupture (MOR), modulus of elasticity (MOE), internal ...
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The effect of using nanoclay on MDF properties was investigated. Sodium montmorolonit (NA+MMT) was used in three levels of 0, 3 and 6 percent based on dry weight of two resins of urea formaldehyde (UF) and Methylene diphenyl diisocyanate (MDI). Modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), thickness swelling (TS) and water absorption (WA) of MDF were measured based on EN standard. Results demonstrated that with the increase of nanoclay in both UF and MDI resins MOR and MOE of MDF increased significantly in such a way that with the use of UF containing 6% nanoclay MOR increased by 33%. Although, IB was significantly affected by UF containing nanoclay, MDI containig nanoclay caused reduction in IB. WA and TS of MDF made from MDI did not show significant variation by increase of nanoclay but those made from UF resin positively affected by adding nanoclay in such a way that MDF made from 3% nanoclay showed 41% loss in TS compared to those made from pure UF.
Research Paper
Mechanical conversion of wood and wooden fittings
amir lashgari
Abstract
In this study, distribution pattern and tension concentration as well as failure prediction in dowel joint were analyzed. The effect of dowel diameter (6, 8, 10 mm) and wood type (Beech, Alder and white spruce) on tension resistance and bending moment were examined. The dimensions for making T-form joints ...
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In this study, distribution pattern and tension concentration as well as failure prediction in dowel joint were analyzed. The effect of dowel diameter (6, 8, 10 mm) and wood type (Beech, Alder and white spruce) on tension resistance and bending moment were examined. The dimensions for making T-form joints were 5×5×2/5 cm. Wooden dowel used in this research was carpinus betulus which accounts as the common dowel in market. Also, PVA was used in Joints. A total of 36Tshape samples comprising 9 combinations of the above factors in 4 replications were made. Tension resistance and bending moment were measured by mechanical test machine. For exertion strength due to analyzing the resistance loading speed equal to 1.25 mm/min were applied. Also, to analyze distribution pattern and tension concentration in affected joints, finite element method and ANSYS Software were used. According to the results of the simulation modeling, joint which endured the maximum tension complied with the real joints. Distribution of tension in the middle of the bending moment depth was greatest and tension in dowel joints was concentrated in impaired points.
Research Paper
Composite wood products
Ali akbar Enayati; Farnaz Eslah
Abstract
This study was conducted to investigate the effect of mixing great size wood particles of poplar with appropriate size particles of the same species, on density profile and physical -mechanical properties of the made particleboard, this study was carried out. One layer boards were made by use of appropriate ...
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This study was conducted to investigate the effect of mixing great size wood particles of poplar with appropriate size particles of the same species, on density profile and physical -mechanical properties of the made particleboard, this study was carried out. One layer boards were made by use of appropriate and great size residue particles on a 7mm pores screen with the ratio of 0/100, 15/85, 30/70, and 45/55 respectively. The results obtained from measured physical and mechanical properties showed that increasing great particles ratio had no negative effect on properties of boards. Increasing the amount of this particles in boards composition, caused increasing internal bonding and decreasing water absorption and thickness swelling levels. In addition, there were no significant differences within boards made from different treatments MOR and MOE properties. Regarding results of this study, when %15 great particles was used with appropriate particle ones, boards had minimum reduction of mechanical strength. Investigation of density profile showed the same result. But all properties of the boards were over the determined limit in terms of relevant standard values even in the case of using 45% great particles.
Research Paper
Physics and Mechanical Wood
Jafar Eskandari; Amir sohil Pirayeshfar; Mohammad mehdi Jalili; Sayed yahya Mosavi; Mehran Rohnia
Abstract
In this study, three composites (Carbon fiber- Polyester resin, Glass fiber-Polyester resin and Hemp fiber-Polyester resin) are designed as a substitute for the wood in music instruments and their acoustic properties such as elastic modulus, acoustic coefficient, and acoustic coefficient efficiency are ...
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In this study, three composites (Carbon fiber- Polyester resin, Glass fiber-Polyester resin and Hemp fiber-Polyester resin) are designed as a substitute for the wood in music instruments and their acoustic properties such as elastic modulus, acoustic coefficient, and acoustic coefficient efficiency are investigated. For better evaluation of the results, two wood specimens from Cupressus arizonica and Morus Alba trees (which are using in many acoustic applications) were chosen and analyzed as control samples. The results show that the resultant composites possess essential acoustic and vibrational properties so that the result for Carbon fiber-Polyester composite exhibits tremendous acoustic properties than wood samples did. In this paper, the water absorption of resultant composites and wood samples were also measured. The results demonstrate that composites specimens could resist against humidity much better than wood samples.
Research Paper
Composite wood products
Fatemeh Taheri; Ali akbar Enayati; Abdol rasol Oromihei; Mehdi Tajvidi
Abstract
By utilizing three different grades of Polypropylene (PP) as matrix, two different kind of MAPP as coupling agent and without MAPP and Pistachio's flour, composite samples were produced. Physical and mechanical properties of wood plastic composites including: MOR, MOE, tensile strength, bending ...
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By utilizing three different grades of Polypropylene (PP) as matrix, two different kind of MAPP as coupling agent and without MAPP and Pistachio's flour, composite samples were produced. Physical and mechanical properties of wood plastic composites including: MOR, MOE, tensile strength, bending strength, impact strength, hardness, water absorption and thickness swelling (816 hours) were determined. Results indicated that the effect of different grade of polypropylene and coupling agent on water absorption, thickness swelling, hardness and impact strength variables were insignificant. Use of Polypropylene having higher Melt Flow Index (MFI) leads to increase in mechanical properties of wood plastic composite samples such as Bending and Tensile strength even if coupling agent wasn't used. Use of different kind of MAPP as coupling age in making wood plastic composites can result in better mechanical properties which based on their type have different effect.
Research Paper
Composite wood products
Ali Byat kashkoli; Morteza Nazaryan
Abstract
Definition of furniture design and its products according to the principles of anthropometry is essential and meaningful. Dimensions of chair should optimize fitting based on anthropometric measurements of population. The research explores the appropriate chair dimension which best fit the anthropometric ...
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Definition of furniture design and its products according to the principles of anthropometry is essential and meaningful. Dimensions of chair should optimize fitting based on anthropometric measurements of population. The research explores the appropriate chair dimension which best fit the anthropometric characteristics of Zabol students. The applied methodologies were descriptive and approximate. Anthropometric measurements of Zabol students, include back height, arm-shoulder to elbow, popliteal height, buttock popliteal height and hip circumference, and statistical analyzes, include Duncan analysis and descriptive statistics used and proper dimension of chair were determinate by the guideline. A total of 140 students (15 female and 20 male representing each of the four bachelor duration) were sampled. Dimension of all chairs variety were recorded. Differences of anthropometric measurements of 60 people were measured to available education chair. The obtained results showed that the chair dimensions were greater than the acceptable limits for most students. If chair dimensions, include armrest height, seat height, seat depth, seat width and backrest height are equal to 20, 42, 38, upwards of 59 and 35 cm, match percent could be improved to 32%, also, 49%, 49%, upwards of 59% and 44%, respectively.
Research Paper
Composite wood products
Hamid Hatefnia; Aliakbar Enayati; Kazem Dosthosseini; Mohammad Azadfalah
Abstract
In this research the effect of steam pretreatment on the physical and mechanical properties of particleboard were evaluated. Steam pre-treatment was applied on the particles of poplar wood in a stainless steel reactor at four different temperature (155, 165, ...
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In this research the effect of steam pretreatment on the physical and mechanical properties of particleboard were evaluated. Steam pre-treatment was applied on the particles of poplar wood in a stainless steel reactor at four different temperature (155, 165, 175 and 185 ◦C) and three different retention time (15, 30 and 45 min). The obtained results indicated that mechanical properties include MOR and IB content of the particleboard decreased, whereas MOE increased initially then decreased with severity of treatment conditions. The physical properties of the board i.e. thickness swelling, water absorption and consequently dimensional stability were improved by steam pretreatment. The observed changes can be attributed to reduction in hemicelluloses content and hydroxyl groups within wood component.
Research Paper
Pulp and paper
Hamd Unesi kord khalili; Mehran Jalilvand; Rabi Behroz
Abstract
The purpose of this study was to investigate effects of different loading levels and addition of urea formaldehyde and polyethylene on the creep behavior of composites made from wastes of OCC recycling mills. The composites manufactured by hot press method and three-point ...
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The purpose of this study was to investigate effects of different loading levels and addition of urea formaldehyde and polyethylene on the creep behavior of composites made from wastes of OCC recycling mills. The composites manufactured by hot press method and three-point bending test performed before creep test. In general, the results showed positive effects of additive materials such as urea formaldehyde and polyethylene on the creep behavior of the composites. While adding UF and PE decreased primary and final creep as well as return deformation percentage of the composites. Also the obtained results indicated that remaining creep had higher sensitivity to loading levels compared to primary and final creep. Also the increase of the load levels from 20% to 30% led to an increase in creep content of the composites.
Research Paper
Composite wood products
Saeid Kazemi najafi; Ali Azimi dalrstani
Abstract
In this study, physical and mechanical properties of composites made of bark flour and polypropylene were studied and compared with those of wood flour-polypropylene composites. Bark flour content were adjusted at three levels (40, 50 and 60%) and compounded at absence and presence of 2% compatibilizer ...
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In this study, physical and mechanical properties of composites made of bark flour and polypropylene were studied and compared with those of wood flour-polypropylene composites. Bark flour content were adjusted at three levels (40, 50 and 60%) and compounded at absence and presence of 2% compatibilizer (MAPP) in a twin screw extruder to produce the bark flour-polypropylene composites. The wood flour-polypropylene composites also were manufactured at 60 filler weight wood flour loading. The results showed that water absorption and thickness swelling of composites containing bark flour increase with increasing bark flour content. The composites containing bark flour exhibited lower water absorption and thickness swelling than those made from wood flour. In absence of MAPP, bark content had no significant effect on flexural modulus of the composites but flexural strength and un-notched Izod impact strength significantly decreased with increase in bark content. The use of MAPP had no significant effect in increasing the mechanical properties. A comparison indicates that in absence of MAPP, bark flour-PP composites exhibited higher mechanical properties than wood flour-PP composite but in presence of MAPP, results were quite inversed.
