Asghar Tarmian; Marjan Ebrahimi; Reza Oladi
Abstract
In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) ...
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In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) were cut from the sapwood and were then dried in laboratory kiln at 50˚C and 50 % relative humidity to final moisture content of 8%. After drying, the severity of casehardening of dried boards was measured using prong test. For anatomical studies and measuring vessel features, white chalk and black marker method was used and scanned sections were analyzed using ImageJ. Pearson correlation was applied between vessel features and drying properties using SPSS software. Results showed that vessel proportion and porosity have more pronounced effect on the drying rate than vessel diameter and the latter feature can be ignored; as drying rate in the free-water domain was lower for oak having larger but fewer vessels than beech. Results also showed that correlation between casehardening and vessel diameter was significantly positive; however, a negative correlation was observed between porosity and casehardening.
Composite wood products
ELHAM MARZBAN MORIDANI; Mohammad Talaeipoor
Abstract
In this study, physical properties of composite produced using recycled polymer (polypropylene and polyethylene) filled with two types of paper mill sludge (sludge on the DAF and waste water sludge) were investigated. Three levels of paper sludge (15, 30 and 45 wt %) were used to produce composites. ...
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In this study, physical properties of composite produced using recycled polymer (polypropylene and polyethylene) filled with two types of paper mill sludge (sludge on the DAF and waste water sludge) were investigated. Three levels of paper sludge (15, 30 and 45 wt %) were used to produce composites. Haake machine was used to blend materials and to produce standard samples; injection molding system was utilized. Density, water absorption and thicknesses swelling of composites were measured. The increasing of both paper mill sludge (sludge on the DAF and wastewater sludge) to the recycled polyethylene and polypropylene increased the density of composites. But, comparing the data obtained from density measurement with literature showed that utilization of paper mill sludge produced relatively lower density and cost on the unit volume basis. Adding both paper mill sludge (sludge on the DAF and waste water sludge) increased water absorption and thicknesses swelling. The samples containing polypropylene and waste water sludge showed lower water absorption and thicknesses swelling compared with other composite.
Composite wood products
Fardad Golbabaei
Abstract
The main purpose of the production of cement or wood products, composite panels by binding mineral particles mixed with organic materials such as wood and mineral lignocellolosic connectors such as cement, plaster, etc. This study was conducted with the objective of investigating the feasibility of making ...
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The main purpose of the production of cement or wood products, composite panels by binding mineral particles mixed with organic materials such as wood and mineral lignocellolosic connectors such as cement, plaster, etc. This study was conducted with the objective of investigating the feasibility of making wood-cement using Poplar sawdust and Portland cement. A total of 30 bricks were made in the laboratories of Wood and production based on ratios of sawdust to cement (5-95, 10-90, 15-85, 25 -75 persent). Mass and volume of samples were measured and then density of bricks was calculated. The composites were tested for compressive strength using testing machine. The mean compressive strength values were 1.75 and 0.38 MPa composites with sawdust to cement ratios of 5-95 and 25-75 respectively, soaked composites swelled irrespective of the sawdust to cement ratio. The compressive strength for the soaked bricks was approximately 40% of the dry weight strength. The composite bricks were found to be unfit for paving and medium heavy load wall construction. Due to their light weight, by imparting decorative mosaics they can be used for interior wall paneling and decoration, where minimal wetting is experienced
Composite wood products
Saeid Esmaeiliymoghadam; Amir Nourbakhsh; seyed mojtaba Seyedzadeh Otaghsaraei
Abstract
This study with aim of evaluation the Nano-silica and wood flour calcareous-treated and evaluation of properties of the wood plastic Nano composite obtained from it performed. For this purpose beginning, wood flour was treated by calcium hydroxide and then with weight ratio of 60 to 40 by Polypropylene ...
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This study with aim of evaluation the Nano-silica and wood flour calcareous-treated and evaluation of properties of the wood plastic Nano composite obtained from it performed. For this purpose beginning, wood flour was treated by calcium hydroxide and then with weight ratio of 60 to 40 by Polypropylene with 4 per hundred compound (phc) MAPP compatibilizer in extruder machine were mixed. Beside, Nano silica with weight ratio of 0, 1, 3 and 5 phc was used. Wood plastic Nano composites were fabricated by injection molding technique. Fourier transform infrared spectroscopy was used from wood flour changes after chemical treatment and for morphological study of Nano composites from scanning electron microscopy and X-ray diffraction were used. Mechanical testes include bending (ASTM D790) and tensile (ASTM D638) and physical testes include water absorption and thickness swelling (ASTM D7031-11) on the samples was done. Results showed that by calcium hydroxide treatment, bending and tensile resistance were decreased but bending and tensile modulus were increased. Also with increasing the Nano silica up to specific range, the mechanical properties were improvement. Increase of Nano silica in untreated samples caused increasing of water absorption and in treated samples caused decreasing of water absorption. With increasing of Nano silica, thickness swelling in the samples was decrease. The results of infrared spectroscopy showed that after lime treatment No change has occurred in the absorption band related to the hydroxyl groups. Results of scanning electron microscopy showed that the needle-shaped crystals of calcium hydroxide formed calcium silicate crystals after addition the Nano silica too. As well as results of X-ray diffraction, confirmed calcium silicate crystals.
Vahid Safdari; Seyyed Peyman Hashemi Beygzadmahalleh; Asghar Tabei; Seyyed Khalil Hosseinihashemi
Abstract
Tobacco (Nicotiana tabacum) is one of the non-wood species and its stalks are the main crop after harvesting which can be used in composite board and paper industry. For better use of this non-wood fibrous raw material, the evaluation of anatomical, morphological and chemical components are necessary. ...
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Tobacco (Nicotiana tabacum) is one of the non-wood species and its stalks are the main crop after harvesting which can be used in composite board and paper industry. For better use of this non-wood fibrous raw material, the evaluation of anatomical, morphological and chemical components are necessary. Tobacco stalks "Coker"cultivar 347 which is widely planted in Gilan province of Iran were randomly sampled. Anatomical properties (cross, tangential and radial sections) and morphological properties (fiber length, fiber diameter, and cell wall thickness) were measured and the indices and ratio of the fibers including: slenderness index, runkel index, flexibility ratio in three heights of stem (5%, 50% and 75%) were calculated. The Chemical components including: Cellulose, lignin, ash, alpha cellulose and hemicellulose of stem with bark and without bark were recorded according to related standards and the results were ststistically analyzed. Results showed that the chemical components of the tobacco stalk were desirable but the index of L/D of fibers were lower than many non-woods and hardwoods. Therefore, it is assumed that the paper produced from tobacco stalks do have suitable tear strength. The runkel index (2 cell wall thickness / fiber diameter) is close to hardwoods and many non-woods, Therefore, it is presumed that paper have appropriate tensile, burst and folding strength. It is predicted that tobacco stalks combined with softwoods with long fibers can produce good quality paper.
Elham Marzban Moridani; Mohammad Talaeipour; Amir houman Hemmasi; esmaeil Ghasemi; Mehdei Kalagar
Abstract
In this research, the mechanical properties of composite produced from recycled polymers (polyethylene and polypropylene) and paper mill sludge from two different sources (waste water sludge (s) and sludge on the DAF) were examined. Three levels of paper sludge (15, 30 and 45 wt %) were used to produce ...
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In this research, the mechanical properties of composite produced from recycled polymers (polyethylene and polypropylene) and paper mill sludge from two different sources (waste water sludge (s) and sludge on the DAF) were examined. Three levels of paper sludge (15, 30 and 45 wt %) were used to produce composites. Haake machine was used to blend materials and to produce standard samples, injection molding system was utilized. The mechanical properties including bending (strength and modulus) and impact strength were measured. The results showed that composites containing PP polymer and waste water sludge have higher mechanical properties than PE polymer and sludge on the DAF. The addition of both types of sludge as filler, results in enhancement of tensile properties compare to pure polymer. In the case, the higher content of sludge on the DAF was used, tensile strength of the composite decreased. Adding both types of sludge as filler, impact strength was lower than pure polymer. It was shown that composites containing sludge on the DAF have lower impact property than waste water sludge.
Pulp and paper
Ali Solimani; Hossein Resalati; Eiman Akbarpoor
Abstract
In this research, effects of mixing the birch wood with hornbeam and beach on optical and physical properties of papers produced at constant freeness range of 300 ml, CSF and yield of 85% and reference of CMP pulp (75% hornbeam plus to 25% beach) was investigated. CMP pulp was produced from birch ...
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In this research, effects of mixing the birch wood with hornbeam and beach on optical and physical properties of papers produced at constant freeness range of 300 ml, CSF and yield of 85% and reference of CMP pulp (75% hornbeam plus to 25% beach) was investigated. CMP pulp was produced from birch chips at 10,20,30 and 40% content within the conditions of pulp yield:85%, liquor to dried chip ratio (L/W) of 7/1, sulfite percent of 20% on oven-dried wood chips, cooking temperature:1600C, cooking time:85-135 minutes blended with 60-90 % hornbeam and beach. After defibration and refining the cooked wood chips, the standard hand sheets of 60 g/m2 were made from different pulps and the optical and physical properties of paper produced were compared. The results from comparing the optical properties of paper showed that using up to 40% birch chips blended with hornbeam and beach led to brightness improvement and yellowness and opacity reduction compared to control CMP pulp. Increase of birch use to 30% indicated no significant effect on opacity values at confidence level of 99% compared to control CMP pulp. Utilizing 40% birch resulted in the preparation of papers with lower caliper, smoother surface and higher air resistance.
Composite wood products
Laya jamali rad; saeed Narooei
Abstract
The purpose of this study was to investigate the possibility of using tobacco stalk and industrial wood particles in particleboard industry as a waste material that is not consumed and discarded and has a low price, followed by a reduction in production costs from the way of choosing this raw material ...
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The purpose of this study was to investigate the possibility of using tobacco stalk and industrial wood particles in particleboard industry as a waste material that is not consumed and discarded and has a low price, followed by a reduction in production costs from the way of choosing this raw material was of low value. For this purpose, the particles of tobacco stalk and industrial wood particles with different ratios of 0:100, 30:70 and 60:40, using the amount of adhesive used 12% and 14% (based on the dry weight of the wood chips) and the press time of 5 minutes for the construction of the board was considered. Physical and mechanical properties including thickness swelling after 2 and 24 hours immersion in water and bending strength (MOR), modulus of elasticity (MOE) and internal bonding (IB) were measured and all data were statistically analyzed. According to the results of this study, the increase in tobacco stalk particles resulted in increased thickness swelling after 2 and 24 hours immersion in water and reduced bending strength, modulus of elasticity and internal bonding, but all boards had a European standard (EN). Increasing the amount of resin also had a significant effect on all the properties of the boards and improved the properties. In a general conclusion and by comparing the properties of the boards produced with the European standard (EN), showed that using 60% tobacco stalk and 12% urea formaldehyde resin can be produced particleboard with the desired properties. This is a positive result of using tobacco stalk as a type of agricultural residue and, consequently, the prevention of environmental pollution caused by the burning of these compounds.
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.
Physics and Mechanical Wood
Hamideh Abdolzadeh; Ghanbar Ebrahimi; Mohammad Layeghi; Mehdi Ghasemieh; Seiad Ahmad Mirshokraei
Abstract
In this study, characteristics of wood-polymer fracture under mode I were investigated by double cantilever beam. In this regard, the properties of furfurylated specimens with three different levels of furfurylation (20%, 30% and 65%) were evaluated in both RL and TL systems. Results indicated that load-displacement ...
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In this study, characteristics of wood-polymer fracture under mode I were investigated by double cantilever beam. In this regard, the properties of furfurylated specimens with three different levels of furfurylation (20%, 30% and 65%) were evaluated in both RL and TL systems. Results indicated that load-displacement curves from mode I fracture specimens were changed by furfurylation so that it was much clear on curves of TL system. These changes not only included curve slope in elastic and proportional limit zones, but also fracture zone and initiation of crack growth were included . Furthermore furfurylation and raising its content on both systems and especially on TL one, caused to change in stress intensity factor, KIC , and critical energy release rate , GIC. In both systems GIC were highly increased by increasing of furfurylation contents. This criterion demonstrated that the wood- polymer showed much toughness under mode I fracture. Moreover, variation of KIC values due to furfurylation at both systems was different with that of GIC. At the RL system, ascending trend was observed at KIC and GIC values by increasing furfurylation levels. But at TL system, KIC was decreased by furfurylation and this criterion enhanced by increasing of furan polymer in the cell wall. Generally, results of this research show that fracture toughness of wood is highly affected by furfurylation process
Pulp and paper
Jaber Hossein zade; Ali Abdolkhani; Mohammad Emami nasab; Hamid Khodabandeh lo; Mohammad Ahmadi
Abstract
In this research Tension Wood (TW) and Normal Wood (NW) of Poplar were analyzed for pulp production using Kraft pulping process. After preparing samples, Biometric characteristics of the NW and TW fibers were measured and samples were converted to pulp. Pulp hand sheets mechanical and physical properties ...
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In this research Tension Wood (TW) and Normal Wood (NW) of Poplar were analyzed for pulp production using Kraft pulping process. After preparing samples, Biometric characteristics of the NW and TW fibers were measured and samples were converted to pulp. Pulp hand sheets mechanical and physical properties were measured and results were showed that NW fibers compared to TW fibers had a higher Rankle coefficient and aspect ratio. However the flexibility of NW fibers was better than TW fibers. Based on Results, although TW pulp yield was 13 percent greater than NW pulp yield but kappa number in TW was 45 percent lower than NW. Mechanical and physical properties of hand sheets indicated that the tensile and burst strengths of tension wood were comparatively lower than that of normal wood. Also the papers produced by equally mixture of TW fibers and NW fibers were showed higher tensile and burst strengths. Optical and color analyses of samples were showed an improvement in brightness and whiteness for TW hand sheets compared to NW papers. General speaking results were showed that presence of TW fibers inside pulp had not a significant effect on quality of produced pulp and papers.
Pulp and paper
Noradin Nazaneghad; seid najeh Mosavi; Seid Majid Zabihzadeh
Abstract
Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of ...
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Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of different treatments. Cationic starch is effective treatment for recycled fibers Promotion. In this study, the cationic starch of Tapioca and Corn, each at three different levels 0.5, 1 and 1.5 % and comparison with samples (without cationic stretch). Hand sheets with a grammag of 120 g/m2 were made and their strength properties were measured. As well as, the absorption rates of two kinds of starch on the pulp were calculated using the Acid- Phenol method. The results indicated that the use of 1.5% of Tapioca starch and 1% Corn starch had an optimum effect in increasing the strength of the produced paper. Concerning the comparison of these different types of starch, the tapioca starch was more effective than the corn starch.
amir lashgari; Payam Khodayari; Seid Ali Mohammadi
Abstract
In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type ...
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In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type joint. The junction have not used out of any adhesive as an adjuvant. From combination of this variable factors and examination of any strength some 24 samples have created,that due to the 4 iterations,96 specimens of L shaped joints have been coustructed totally.the bending and tensile strength of produced junction has been measured by mechanical test machine.based on captured results the interaction of constituents of,nail penetration length,nails number and members nature on joint strenght weren′t significant in front of tensile and bending.this research indicated that the junctions with the penetration length of 48 mm,the most amount of nail(three nails)on MDF member elements,have the greatest strength against bending strength,and the link with penetration length of 42mm alone with the most amount of nail(3 nails)on MDF have the greatest strength against tensile,as copared with each other.
Mohammad Ghofrani; Sakineh Pishan; Aysona Talaei
Abstract
Increasing demand for light and durable materials in home and office furniture requires optimizing the properties of the products used. In this research the effect of skin type and core on mechanical properties of light weight sandwich panel was investigated. The skins were made of MDF with ...
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Increasing demand for light and durable materials in home and office furniture requires optimizing the properties of the products used. In this research the effect of skin type and core on mechanical properties of light weight sandwich panel was investigated. The skins were made of MDF with 3, 6 and 8 mm thickness, particle board with 8 mm thickness, three layer plywood with 3.8 mm thickness and five layers plywood with 7.28mm thickness. The cores of polyurethane foam and honeycomb of kraft paper (3 cm thickness) were used. Mechanical tests including bending strength, modulus of elasticity; impact bending and compression were performed according to DIN and ASTM standards. Result showed that, light sandwich panels made from polyurethane foam core had higher mechanical properties than the light panel made of kraft honeycomb core which indicates that the dense and homogenous structure and better linkage with skin. By increasing the thickness of skin in the samples made from MDF skin, the properties of sandwich panel increased. The best result of mechanical properties was observed in light weight sandwich panel made of plywood skin and polyurethane core.
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.
Pulp and paper
Said mohammad Mazhari mosavi; Saeed Mahdavi; Syed zyaldin Hosseini; Hossein Resalti; Hossein Usefi
Abstract
This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. ...
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This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. Cellulose, lignin, extractive material (acetone solved) and ash were measured 41.66, 16.00, 1.63, and3.46 percent, respectively. Cooking condition was determined as follow: Soda as 16, 18, and 20 percent on the basis of rapeseed dry straw, temperature was set at 175 and 185 Cº, cooking time was set at 40 and 70 minutes, and straw to liquid ratio was set at 1/8. The amount of anthraquinone added to cooking liquor was 0.2%, based on rapeseed dry straw. Using severe cooking factors caused reduction of yield and Kappa number in both methods. Refining was performed on selected pulps in order to reach 35025 (ml,CSF) freeness. The 60 gr/m² hand sheets were made in order to determine mechanical strength and physical properties. Average thickness, density and bulk is measured at 86.4µ, 0.69gr/cm³ and 1.44cm³/gr respectively. Average tear index, burst index, breaking length and tensile indexare measured at 4.6 mN.m²/gr, 3.5 kpa.m²/gr, 7.4km and 72.6Nm/g respectively.
The results showed that however screen yield of rapeseed straw pulp is low but kappa number and mechanical properties of pulp is suitable,compared with the other agriculture residues, so Rapeseed pulp can be used in paper making industries.
Pulp and paper
Saeed Mahdavi; masoudreza habibi; kermanian hossein
Abstract
Global concerns for preservation of forests and elimination of pollution from pulping and papermaking processes has led us to explore alternate fibrous resources other than wood and new environmentally begin pulping and bleaching processes for papermaking without sacrificing quality. Various alternate ...
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Global concerns for preservation of forests and elimination of pollution from pulping and papermaking processes has led us to explore alternate fibrous resources other than wood and new environmentally begin pulping and bleaching processes for papermaking without sacrificing quality. Various alternate fibrous resources such as agricultural residues are already in use in many countries and considerable research have been undertaken to produce pulps by conventional and non-conventional processes. Wheat straw has high quantity among agricultural residues in Iran. Kraft, Soda and Ethanol-alkali pulping were carried out after sampling and preparing of wheat straw. Retention of carbohydrates is improved compared to the alkaline pulping processes, resulting in about 8 to 15 % higher yield at the same level of residual lignin. There was lower energy consumption for refining Ethanol-alkali pulps. There were no statistical differences among the physical properties. The strengths of Ethanol-alkali pulps consist of tear index, burst index and breaking length were lower than alkaline pulps, but all of the strength properties were higher than kraft and liner paper except tear index that addition of some long fiber can solve the problem.
Management and Economics wood
Mehrab Madhoushi; Vajihe Mojerian Galogahi; Mohammadreza Masteri Farahani
Abstract
Radiography is a method of non-destructive for evaluating the quality of wood construction machinery in order to detect the defects due to natural degradation. The objective of this study was to investigate the assessment of Poplar (Populus deltoides) and beech (Fagus orientalis) wood defects arising ...
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Radiography is a method of non-destructive for evaluating the quality of wood construction machinery in order to detect the defects due to natural degradation. The objective of this study was to investigate the assessment of Poplar (Populus deltoides) and beech (Fagus orientalis) wood defects arising from the decaying by using x-ray non-destructive method. In this study, for each of species, uncolored (no coating) and colored samples by acid catalyzed lacquers and nitrocellulose lacquers were used. Decay resistance test based on modified ASTM D1413 standard was performed. The decay process was done in the periods of 1, 2 and 3 months with use of Coriolus versicolor fungus at laboratory condition. After each of these periods, for the decay of the samples, x-ray imaging by using an imaging at the lateral, tangential and radial direction was done. Results of weight loss confirmed the presence of decay in the radiographic images. The results showed that after 1, 2 and 3 months of exposure to fungus, fungal degradation leads to weight loss in the painted and unpainted samples. So that, the weight loss caused by decay in beech was less than poplar samples. As well, the weight loss of unpainted was less than painted samples, which was also statistically significant. The x-ray results of unpainted and painted samples at the cross, tangential and radial directions indicate that decay has a more impact on beech in comparison to poplar wood structure. The study as well showed that the protective layer has partly a barrier for decay destruction in these samples.
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.
Management and Economics wood
seyed amirabbas namaki
Abstract
Abstract In this paper, we attempted to investigate the relationship between consumption, demand for imports of fine paper and economic growth using annual time series data in the period of 1984 to 2010. Since the time series are non-stationary (Unit root) and can lead to spurious regression, the stationary ...
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Abstract In this paper, we attempted to investigate the relationship between consumption, demand for imports of fine paper and economic growth using annual time series data in the period of 1984 to 2010. Since the time series are non-stationary (Unit root) and can lead to spurious regression, the stationary of the variables are investigated in its logarithmic form using Augmented Dickey Fuller test (ADF) in two type of intercept without trend and intercept with trend. After applying the unit root test, in order to understand the interaction between economic growth and consumption and imports of fine papers and direction the causal relation, the vector auto regressive (VAR) approach including two models and the causality test of granger are used.The results indicate that GDP growth will increase the consumption of writing and printing papers but this relation is one-sided. On the other hand, there is no causality between changes in GDP and imports of printing and writing paper, and vice versa. Also, there is the one-side causality between GDP and consumption of newsprint. In the case ofThe Granger causality between economic growth and imports of newsprint, due to reject the null hypothesis, there was no relationship found, and vice versa
Mechanical conversion of wood and wooden fittings
Hamideh Abdolzadeh; Ghanbar Ebrahimi; Mohammad Layeghi
Abstract
In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used and hand ...
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In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used and hand lay-up was done by vinyl ester and epoxy resins. Results of load-displacement curve at yield point exhibited capability of the reinforcing layers in preventing joint opening to some extent under load. However, failure was observed at the joint due to picking fibers from wood surface or members fracture near the interface when loading increased. Since the reinforced zones of the joints by FRP show the maximum shear stress, consequently the separation of fibers from wood surfaces increased at these locations. The adhesion of FRP layers to joint surface was not appropriate due to difficult process of layering at right angle of joints followed by probable formation of air bubbles. The results of assessing FRPs reinforcing behaviour indicated that application of vinyl ester in comparison with epoxy as matrix exhibited better performance. In addition, glass and carbon fibers showed better performance than Kevlar fibers as reinforcing agents.
Pulp and paper
Mina Akbari; Ghasem asadpour; noorodin nazarnezhad
Abstract
As a result of water treatment and during the water softening and hardness reducing process, calcium carbonate deposits with other impurities produced, collected and buried as mineral sludge. This study was done to investigate the effect of using calcium carbonate filler (as a byproduct of water treatment ...
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As a result of water treatment and during the water softening and hardness reducing process, calcium carbonate deposits with other impurities produced, collected and buried as mineral sludge. This study was done to investigate the effect of using calcium carbonate filler (as a byproduct of water treatment process in Mazandaran wood and paper mill) on strength properties of fluting paper produced from both old corrugated container (OCC) and neutral sulfite semi chemical(NSSC) pulps. Calcium carbonate added to the pulps at levels of 5, 10 and 15 percentage of bone dry weight of paper. The air resistant with the tensile index, burst index, tear index and resistant to fluting of handsheets were measured and compared to control handsheets (samples without calcium carbonate). The results showed that the use of calcium carbonate from the water treatment has a negative impact on fluting paper strength properties. Calcium carbonate filler negative impacts on virgin pulp (NSSC) and recycled pulp (OCC) is different and is more in OCC pulp.
Composite wood products
masih masoudifar; Babak Nosrati; Hamid reza Mansori; Rahim Mohebi gargari
Abstract
This study aimed to investigate the effect of chemical treatment of wood material on functional properties of wood flour / polypropylene hybrid composite. For this reason, first of all, mixed hardwood were separately treated by acetic acid, sodium hydroxide and hot water and were compared with control ...
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This study aimed to investigate the effect of chemical treatment of wood material on functional properties of wood flour / polypropylene hybrid composite. For this reason, first of all, mixed hardwood were separately treated by acetic acid, sodium hydroxide and hot water and were compared with control (untreated) samples. After chemical treatment, wood flour and polypropylene with weight ratio of 50 to 50 and 3 phc of compatibilizer combines in the internal mixer and at last the WPC composite were made using injection molding. Then mechanical tests included bending resistance, tension and impact and physical examination, including water absorption and thickness swelling after 2 and 24 hours was performed on specimens according to (ASTM) standard. Also to study the morphology of the composites, scanning electron microscopy (SEM) was used. The results of this study showed that by chemical treatment the mechanical strength increased and physical properties such as water absorption and thickness swelling decreased. So that the highest flexural strength, tensile and flexural modulus is related to alkali treatment and the highest tensile modulus and impact resistance is related to the acid treatment. Also the lowest water absorption and thickness swelling was related to the alkali treatment. In order to ensure chemical treatments, Fourier transform infrared (FTIR) and weight percent gain (WPG) was used on wood flour.
Hamed Matini behzad; Asghar Taremian
Abstract
Poplar wood flour was spray treated with two preservative materials, (Thiabendazole or Carbamate derivatives (IPBC) with concentration of 0.9%) and then the wood/polyethylene composite samples with the composition of 60% wood, 38% polyethylene and 2% coupling agent were manufactured. The treated composite ...
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Poplar wood flour was spray treated with two preservative materials, (Thiabendazole or Carbamate derivatives (IPBC) with concentration of 0.9%) and then the wood/polyethylene composite samples with the composition of 60% wood, 38% polyethylene and 2% coupling agent were manufactured. The treated composite and control samples were exposed to weathering for 5 months using ASTM D1435 standard test method and the structural changes of the samples were analyzed using SEM microscopy. The roughness of WPCs was measured by roughness measuring device (Miyutoyo SJ 201P) before and after weathering. The SEM images showed that the highest surface changes due to weathering occurred in untreated samples. Both preservatives improved the weathering resistance of treated WPC. The differences in the roughness values root mean square roughness (Rq), mean peak-to-valley height (Rz) and average roughness (Ra) before and after weathering were measured as 7.93, 38 and 4.88µm for control samples, 1.65, 21.7 and 42.2 µm for Thiabendazole-treated and 1.2, 1.5 and 0.79 µm for IPBC-treated samples, respectively. Both preservative materials significantly improved the weathering resistance of WPCs.
Vahid reza ُSafdari; Behzad Shabani; Seyyed Khalil Hosseinihashemi; Mehran Roohnia; Vilma Bayamzadeh
Abstract
Air pollutantion in particular pollutants from automobile exhaust can affect anatomical and morphological characteristics of woods. In order to investigate the impact of this factor, Pinus eldarica trees of Chitgar park in Tehran, the area which is extended from south to crowded highway (polluted ...
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Air pollutantion in particular pollutants from automobile exhaust can affect anatomical and morphological characteristics of woods. In order to investigate the impact of this factor, Pinus eldarica trees of Chitgar park in Tehran, the area which is extended from south to crowded highway (polluted site) and in north to Alborz Mountain (unpolluted site) and the middle part (semi-polluted site) were sampled by increment borer. After cross-dating, the tree rings of recent 5 years were separated from the old rings. Then anatomical characteristics of cross section, including transition between early and latewood, tangential thickness of last formed latewood tracheides, frequency of ray and resin ducts and morphological characteristics of tracheids in three zones and in the same rings were studied. Results indicated that the ring width pattern of Pinus eldarica in three zones is somehow the same. The frequency of resin duct and rays and false rings in 2005 and 2006 in the polluted and semi-polluted site were higher compare to the unpolluted site. Fiber length, wall thickness (2d) and lumen size of trees of unpolluted site were more than the other two sites (Polluted and Semi-polluted). In general, it could be concluded that air pollution impact on tree ring width can reduce wood quality as well.
