Research Paper
Composite wood products
Amir Nourbakhsh; Abolfazl Kargarfard; Fardad Golbabaei
Abstract
The goal of this study was to investigate the use of bagasse fibers as raw material for making laboratory medium density fiberboard (MDF). Effect of treatment (with maleic anhydride and without maleic anhydride) of fibers and the press temperatures (180 ºC , 190 ºC , and 200 ºC) ...
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The goal of this study was to investigate the use of bagasse fibers as raw material for making laboratory medium density fiberboard (MDF). Effect of treatment (with maleic anhydride and without maleic anhydride) of fibers and the press temperatures (180 ºC , 190 ºC , and 200 ºC) on the mechanical and dimensional stability properties of MDF panels were determined. Physical (thickness swelling, water absorption, and swilling in water at ambient temperatures and in steam for 12-216 h.) and mechanical properties (modulus of rupture, modulus of elasticity, and internal bond strength) of the panels were determined according to the procedure of EN standards.This study showed all MDF panels made from bagasse fibers treated with maleic anhydride (MA) at 190 ºC press temperature had the highest values among the other types of specimens for general purpose boards. The thickness swelling and water absorption value with treated bagasse fibers and 190 ºC press temperature were very lower than all MDF panels. Treated bagasse fibers at 190 ºC show a minimum steam absorption. The absorption of steam increase with increase in time from 2 to 120 h in all the six treatments. Beyond 120 h. no additional absorption of steam is found in any of the six MDF boards.
Research Paper
Pulp and paper
Abbas Fakhryan roghani; Fardad Golbabaei; Hossein Hosseinkhani; Kamyar Salehi; Saeed Mahdavi; Sabrineh Mohsseni tavakoli
Abstract
In this reseach, chemical, anatomical and pulping properties of 12 years old Populus.triplo of adapting plan and quantity properties of this tree from karaj research station were investigated.The average of fiber length ,diameter ,lumen and thickness of cell wall 1.27 mm ,31.88 um, 23.54 um and 4.22 ...
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In this reseach, chemical, anatomical and pulping properties of 12 years old Populus.triplo of adapting plan and quantity properties of this tree from karaj research station were investigated.The average of fiber length ,diameter ,lumen and thickness of cell wall 1.27 mm ,31.88 um, 23.54 um and 4.22 um and cellulose ,lignin , Ext. and ash %53.74 , %22.87 , %1.8 and %1.5 were measured respectively.The yield and kappa number of pulps between 41.152% - 48% and 18.06 – 25.28 were measured.In 14% and 18% effective alcoholli, tearh index 9.307 mNm²/gr and 10.147 mNm²/gr were obtained.
Research Paper
Physics and Mechanical Wood
Morteza Mostafazadeh mrznaki; Saeid kazemi najafi; Majid Chaharmahali; Reza Hajihassani
Abstract
In study, the influence of flour content and immersion time in water on the creep behavior of composites made from mixes PB (Particle Board) and MDF (Medium Density Fiber Board) flour and high density polyethylene (HDPE) waste and was investigated. Mixing was done by a twin screw extruder and the sample ...
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In study, the influence of flour content and immersion time in water on the creep behavior of composites made from mixes PB (Particle Board) and MDF (Medium Density Fiber Board) flour and high density polyethylene (HDPE) waste and was investigated. Mixing was done by a twin screw extruder and the sample was manufactured by flat hot press. Firstly, the modulus of elasticity and bending strength of various mixes PB and MDF flour-polyethylene composites (WPCS) were measured before performing the creep test.It was shown that the modulus of WPCs increases with the increase in mixes PB and MDF flour content from 60% to 70% and then decreases as the flour content reaches to 80%. It is found that the bending strengths of WPCs significantly and linearly decreases with the increase in flour content from 60% to 80%. The results showed that, the creep strain decreases as the lignocellulosic flour level increases. Water absorption has negative effect on creep behavior of mixes PB and MDF flour/HDPE composites. For all filler contents, it can be seen that the creep strain increases when the immersion time increases.
Research Paper
Physics and Mechanical Wood
Morteza Khorami; Ahmad amin Khalili tabas; Amir Nourbakhsh
Abstract
Cement board without fibres has low flexural strength and fails in small strain. To solve this problem and enhance other characteristics, the fibres are applied. Asbestos fibres which have individual properties have been used for reinforcing cement composites since the early 20th century. However in ...
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Cement board without fibres has low flexural strength and fails in small strain. To solve this problem and enhance other characteristics, the fibres are applied. Asbestos fibres which have individual properties have been used for reinforcing cement composites since the early 20th century. However in this decade, most countries have been banned the use of asbestos fibres in construction industries, because of its effect on human healthy. Natural fibres are one of the suitable alternatives for cement board production that have a good compatibility with cement matrix. In this research, to recognize the flexural behaviour which is the one of the most important characteristics for cement board, many laboratory samples have been made by three kinds of fibres and tested. These fibres obtained from agricultural wastes such as bagasse, wheat and eucalyptus. The scanning Electronic Microscopic studies were carried out to clarify the microstructures of composites. The results show that among the all types of fibres, bagasse has the most effect on increasing the flexural strength capacity for cement composite boards.
Research Paper
mohammad ghofrani; Habib Nori
Abstract
In the present study the strength of different kinds of wooden dowels, screws, and ready-to-assemble joints (RTA joints) used in medium density fiberboards (MDF) were assessed and compared for their lateral shear strength. The T-form specimens (20 cm × 8 cm) were comprised of two MDF parts in compliance ...
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In the present study the strength of different kinds of wooden dowels, screws, and ready-to-assemble joints (RTA joints) used in medium density fiberboards (MDF) were assessed and compared for their lateral shear strength. The T-form specimens (20 cm × 8 cm) were comprised of two MDF parts in compliance with ASTM D1761 standard. Five specimens for each treatment were made and a total of 20 treatments were designed; treatments in this study are as follows:Rough as well as smooth dowel joints with 8 and 10 mm diameter, using urea-formaldehyde and poly-vinyl acetate adhesives; Screw joints, sizes 5 and 6, with or without urea-formaldehyde as well as poly-vinyl acetate adhesives; And, different kinds of RTA joints.Results indicate that different kinds of screw joints show the most powerful joints in comparison with other kinds of joints; but there was no significant difference between different kinds of screw joints. Therefore, having economical points of view in mind, screw joints size 5 is recommended to be used without adhesive. The effect of dowel surface as independent variable was statistically significant, while the interaction effect of dowel diameter, adhesive, and quality of dowel surface on lateral shear strength, as well as the independent and interaction effects of two factors of combined wooden dowel along with joint, and adhesive on the strength of RTA joint (that has nuts) were statistically significant.
Research Paper
Composite wood products
Fataneh Azad; Mohammad mehdi Faezipoor; Mehdi Tajvidi
Abstract
In order to investigate the effect of compatibilizer, (MAPP), on physical and mechanical properties of reed stem flour- polypropylene composites, 60 mesh size reed stem flour particles were compounded at 60% and 70% by weight with a polypropylene homopolymer with a melt flow index of 18 g/10min. Two ...
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In order to investigate the effect of compatibilizer, (MAPP), on physical and mechanical properties of reed stem flour- polypropylene composites, 60 mesh size reed stem flour particles were compounded at 60% and 70% by weight with a polypropylene homopolymer with a melt flow index of 18 g/10min. Two compounds were prepared from which formulations with 60 mesh particle size and 60% and 70% filler loading were selected to evaluate the role of the compatibilizer. One of them was without MAPP and the other one had 3% MAPP by weight. Totally, 4 compounds were prepared. Composites were produced using a twin screw counter rotating extruder. Then, mechanical tests including static flexural test, tensile test, Izod impact test and hardness test were carried out. Physical tests including water absorption and thickness swelling were also performed. All testing was in accordance with ASTM D7031-04 specification. The results of physical tests have indicated that by the increase in reed flour content, maximum water absorption and maximum thickness swelling increased. Generally, by adding the coupling agent (MAPP), the physical and mechanical properties significantly improved.
Research Paper
Composite wood products
Ali akbar Enayati; Marzyeh Raeisi; Hamidreza Adalat
Abstract
For this study, the pruning of Apricot tree and industrial wood particles were used. The combination percent of Apricot wood particles (0, 15, 30 and 45) and press time (5 and 7 minute) were the variables of experiment. Results showed that with increasing the percent of Apricot wood particles, the amount ...
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For this study, the pruning of Apricot tree and industrial wood particles were used. The combination percent of Apricot wood particles (0, 15, 30 and 45) and press time (5 and 7 minute) were the variables of experiment. Results showed that with increasing the percent of Apricot wood particles, the amount of MOE and MOR of panels enhance significantly. Despite the internal bonding (IB) strength of panels decreased with this enhancement, the strength of panels had higher amount than its standard amount. The water absorption resistance and the thickness swelling of panels for 24 hours were improved significantly with increasing the Apricot wood particles percent. In all cases, the effect of press time was not significant. Finally, the combination of 45% Apricot pruning and the shorter press time (5 min) was identified as the best treatment.
Research Paper
Pulp and paper
Mohammad Azadfallah; Arezo Noori
Abstract
Yellowing of lignin-rich mechanical pulp is mainly attributed to light-induced changes in lignin structure. Hence, in this study the photodegradation of milled wood lignin (MWL) prepared from hardwood bleached chemimechanical pulp (BCMP) was investigated. The lignin preparation was then impregnated on ...
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Yellowing of lignin-rich mechanical pulp is mainly attributed to light-induced changes in lignin structure. Hence, in this study the photodegradation of milled wood lignin (MWL) prepared from hardwood bleached chemimechanical pulp (BCMP) was investigated. The lignin preparation was then impregnated on Whatman filter paper and irradiated with UV light during 4 hour exposure time. Then, photodegraded lignin was recovered and characterized by 13C-NMR.Irradiation caused to β-O-4 bonds cleavage, increase in carboxylic and phenolic hydroxyl groups, decrease in methoxyl, primary and secondary hydroxyl group. The amount of β-β and β-5 condensation structures was increased during irradiation.
Research Paper
Pulp and paper
Ali Khalili gasht rodkhani; Ali Ghasemian; Ahmad reza Saraeyan; Mohammad Dahmardeh ghale no; Sayed mehdi Manzorolajdad
Abstract
This study was aimed to investigate the effects of mixing OCC fibers with mixed hardwoods kraft pulp at Iran Wood and Paper Industry Co (Chuka). OCC has been repulped according to the common method in paper recycling industry and its freeness, along with that of virgin kraft pulp, were measured. The ...
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This study was aimed to investigate the effects of mixing OCC fibers with mixed hardwoods kraft pulp at Iran Wood and Paper Industry Co (Chuka). OCC has been repulped according to the common method in paper recycling industry and its freeness, along with that of virgin kraft pulp, were measured. The pulps were beaten to reach the required freeness values to make kraft liner paper, and have been then mixed at 10/90, 20/80, 30/70, 50/50 and 70/30 percentage rates of OCC and virgin kraft pulp, respectively. Handsheets were made from each composition and their mechanical and optical properties have been measured, according to required standard test methods, and compared with those of the control (100% virgin kraft pulp), using ANOVA method. Grouping of the mean values was done by Duncan test and normalization equation was computed to determine the best treatment. The results indicate decreasing the values of tensile, tear and burst, folding endurance and density in comparison with those of the control (100% virgin kraft pulp), but bulk, thickness and opacity have been increased. The score belonging to each treatment show to produce paper possessing proper mechanical and optical properties using OCC fibers, the allowed proportion of these fibers is 50 percent.
Research Paper
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.
Research Paper
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.
Research Paper
Pulp and paper
Hossein Resalti; Morteza Abdolah bik marandi; Ahmad reza Saraeyan
Abstract
The effect of using commercial xylanase enzyme in prebleaching of bagasse kraft pulp was investigated. Xylanase enzyme from Trichoderma viride was added to pulp at various doses of 10, 25 and 50 IU/g pulp for reaction time 2h and then the enzyme treated pulp was bleached in ADED sequences (Acid sulfuric ...
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The effect of using commercial xylanase enzyme in prebleaching of bagasse kraft pulp was investigated. Xylanase enzyme from Trichoderma viride was added to pulp at various doses of 10, 25 and 50 IU/g pulp for reaction time 2h and then the enzyme treated pulp was bleached in ADED sequences (Acid sulfuric +Dioxide chlorine 4, 6, 8, 10% + Alkaline extraction + Dioxide chlorine 2% as available chlorine). The results have shown that with increased dioxide chlorine in D1 bleaching sequence, final brightness of bleached pulp was increased significantly (P<0.01). Furthermore, in the case of treated samples by xylanase enzyme optical properties of bleached pulp such as brightness and opacity were increased significantly (P<0.01). For yellowness, revolution of refiner for distinct pulp freeness and kappa number have shown decreased significantly (P<0.01). Maximum of brightness and minimum of kappa number and yellowness were belong to 25 IU/g pulp treatment that about 10.8, 3.98% and 2.24 unit have difference significantly (P<0.01) as compared with control sample respectively. Maximum of opacity and Minimum was belong to 50IU/g pulp treatment that about 3 and 13.24% have difference significantly as compared with control sample respectively. Regardless of obtained results 25IU/g pulp treatment could be selected as optimal treatment.
Research Paper
Pulp and paper
Noraldin Nazarnezhad; Mohammad taghi Asdolahzadeh
Abstract
This study was investigated the effect of Trametes versicolor on chemimechanical pulp (CMP) delignification. CMP were obtained from Mazanderan wood and paper industries. Circle mats were made from CMP (diameter, 7cm; thickness, 1mm) and fortified with 1g/Lit yeast juice. After sterilized, pulp mats were ...
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This study was investigated the effect of Trametes versicolor on chemimechanical pulp (CMP) delignification. CMP were obtained from Mazanderan wood and paper industries. Circle mats were made from CMP (diameter, 7cm; thickness, 1mm) and fortified with 1g/Lit yeast juice. After sterilized, pulp mats were incubated with tow disks punched from mycelium. The duration of incubate were 5, 10, 15 & 20 days as well as temperature and moisture 25oC and 40%, respectively. Standard hand sheets were made from biodelignification pulp, and was measured mechanical and optical properties. The portion of biodelignification pulp was alkaline extracted under condition of pulp consistency, 10%; temperature, 70oC; time, 80min and 2% sodium hydroxide, and then bleached under conditions of pulp consistency, 10%; temperature, 50oC; time, 60min and 4% hydrogen peroxide. Finally, mechanical and optical properties of standard hand sheet were measured. Results showed optimum time was 10 days that decreased 5.9% lignin. Mechanical properties of treated samples were lower than control samples, but statically were not significant. Optical properties of treated samples were lower than control samples but alkaline extraction and then bleaching with sodium peroxide was increase it.
Research Paper
Physics and anatomy
Alireza Ghotibi far; Saeid Kazemi najafi; Rabi Behroz
Abstract
This research focused on the influence of content (5, 10 and 15 %) of glass fiber on the water absorption and thickness swelling of wood flour/E-glass fiber hybrid polypropylene composites without and with MAPP. The samples (strips with 10 mm thickness and 70 mm width) were made using a laboratory twin-screw ...
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This research focused on the influence of content (5, 10 and 15 %) of glass fiber on the water absorption and thickness swelling of wood flour/E-glass fiber hybrid polypropylene composites without and with MAPP. The samples (strips with 10 mm thickness and 70 mm width) were made using a laboratory twin-screw extruder. The water absorption and thickness swelling of the composites after 2h and 24h were determined. The results showed that adding glass fiber significantly increase water absorption and thickness swelling after 2h and 24h in absence of MAPP. Whereas in presence of 2% MAPP by addition glass fiber, no significant changes were observed in water absorption and thickness swelling of the composites after 2h and 24h. MAPP considerably decreased the water absorption and thickness swelling of the studied composites
Research Paper
Pulp and paper
Mohammad Talaeipoor; Habib alah Khademi eslam; Khodadad Malmir chegini
Abstract
Effect of roughness & water absorption of paper and ink characteristics on optical properties was investigated. For this purpose three type of paper and four type of printing ink was used.Then characteristics of paper & ink was measured. Inks on sampled papers Printed and then L, ...
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Effect of roughness & water absorption of paper and ink characteristics on optical properties was investigated. For this purpose three type of paper and four type of printing ink was used.Then characteristics of paper & ink was measured. Inks on sampled papers Printed and then L, a & b was measured. Result indicated that the effect of roughness and water absorption on L, a & b are not significant. But Solid content, PH and particles diameter of four type of ink on L, a & b have significant effect
