Sina Modirahmati; Ahmad Jahan Latibari; Amir Nourbakhsh; Mehran Roohnia; Mansor Minaei
Abstract
The impact of nanoclay addition on the properties of polypropylene/ OCC fibers/ nanoclay Composite was investigated. Composites were prepared using 67% polypropylene, 30% OCC fiber, 3% MAPP and three dosages (2.5, 5, 7.5% based on total weight of PP/OCC/MAPP) of nanoclay. Premix- ...
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The impact of nanoclay addition on the properties of polypropylene/ OCC fibers/ nanoclay Composite was investigated. Composites were prepared using 67% polypropylene, 30% OCC fiber, 3% MAPP and three dosages (2.5, 5, 7.5% based on total weight of PP/OCC/MAPP) of nanoclay. Premix- melting of nanoclay and polypropylene was used to add nanoclay to the composite mixture. Pre-mixed nanoclay/ polypropylene was melt-mixed with OCC fibers and MAPP and then test samples were made using this compound. The results revealed that addition of nanoclay to polypropylene/OCC fiber composite reduced flexural strength , tensile strength and notched Izod impact strength, but the flexural modulus and tensile modulus of final composite were improved significantly. The influence of nanoclay addition on flexural strength and tensile modulus of composite was statistically significant at 99% level whereas its effect on tensile strength was statistically significant at 95%. However, the effect of nanoclay on both flexural modulus of elasticity and impact strength was not statistically significant. The addition of nanoclay to the composite reduces the bonding between polypropylene and OCC fibers. In the case of notched Izod strength, nanoclay particles generated stress concentration point within the composite structure initiating easier failure. Water absorption after 2 and 24 hours immersion was reduced.
Research Paper
Mostafa Jafari
Abstract
Environmental and climatic conditions influence growth of the trees as well as beech (Fagus orientalis Lipsky), a species which is widely spread in the Hyrcanian forests in northern region of Iran. However, in the northern border of the forests, Oak (Quercus macranthera) dominates. Despite the ...
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Environmental and climatic conditions influence growth of the trees as well as beech (Fagus orientalis Lipsky), a species which is widely spread in the Hyrcanian forests in northern region of Iran. However, in the northern border of the forests, Oak (Quercus macranthera) dominates. Despite the variation in the growth and environmental preferences of beech and oak trees, but experiencing similar climatic and environmental impacts. Therefore, the response of the species could be evaluated simulteneously in various watershed districts. Height and standing volume of Fagus orientalis Lipsky and Quercus castaneifolia as wood producing criteria in response to changes in precipitation, temperature, evaporation, longitude, latitude, elevation and ratio of forest cover to total watershed areas across Hyrcanian forest from Astara to Golidaghi-Golestan was investigated. Results showed, mean forest cover elevation increase significantly with increase in longitude but decreased as latitude increases. The ratio of forest covers to total watershed district areas decreased with increasing longitude and latitude. K-means Cluster Analysis for all variables has been done in 2, 3, 4, and 5 cluster groups using SPSS statistical software to produce cluster dendrograms. In all cluster groups, forests category groups were; height and volume of beech, height and volume of oak, precipitation, the ratio of forest cover area to total areas of watershed districts and temperature, The outcome of this research showed that, beech and oak wood production and growth are primarily affected by the precipitation, the ratio of forest cover to total watershed areas and the temperature, and in the secondary level by longitude, latitude and evaporation. Pearson Correlation at the significance levels of 0.01 and 0.05 are presented.
Research Paper
Mania Jadidi; Noraldin Neghad; Majid Zabihzadeh
Abstract
This research was conducted to find a procedure to increase the optical and strength properties of papers made from oxidized waste newspaper fibers. Samples of waste newspapers were randomly selected and deinked, then one part of deinked pulp was refined. Both refined and unrefined recycled pulp ...
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This research was conducted to find a procedure to increase the optical and strength properties of papers made from oxidized waste newspaper fibers. Samples of waste newspapers were randomly selected and deinked, then one part of deinked pulp was refined. Both refined and unrefined recycled pulp were divided into two groups. In each case, a group of pulps was used to make standard hand sheets (control samples) without hydrogen peroxide treatment and only adding 2% cationic starch. Second group was subjected to different percentages of hydrogen peroxide (2%, 3% & 4%) in alkaline conditions, then 2% cationic starch was added to oxidized fibers prior to hand sheeting preparation and then standard hand sheets were made. Opticaland strength properties of all hand sheets were determined according to TAPPI standards. Also FTIR spectra was taken to specify the effect of oxidation on surfaces of pulp fibers. Results showed that treatment with oxidizing agent increased the strength indices of papers. This increase was more evident when 3% hydrogen peroxide was applied. The strengths of the control samples were the lowest. Moreover, refining imposed the positive effect on strength properties. Results of optical properties measurements indicated that as the extent of treatment for both refined and unrefined pulps increases, the brightness increased, and both the yellowness and opacity decreased. The highest brightness was reached when 3% peroxide was used. Also refining results in increased in brightness and yellowness but decreas opacity. FTIR spectra showed that samples of oxidized pulp had the greatest absorption at wave number of 1650 which pertains to carboxyl group.
Research Paper
amir lashgari; Mohssen Ahmadi
Abstract
Aim of this study were to examine the effects of pin diameter (6, 8 and 10 millimeter), the pins interval ( 30,50 and 70 millimeter), wooden pin penetration depth (2d,3d and 4d D=Diameter of pin) and the shape of H joint on bending strength of the joint. In order to make the H joints, the dimension of ...
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Aim of this study were to examine the effects of pin diameter (6, 8 and 10 millimeter), the pins interval ( 30,50 and 70 millimeter), wooden pin penetration depth (2d,3d and 4d D=Diameter of pin) and the shape of H joint on bending strength of the joint. In order to make the H joints, the dimension of the middle member was selected as 200x125x16 millimeter and the dimension of the side members were selected as 250x125x16 millimeter. MDF was used to make the joints. The wooden pin used in the present research was made from hornbeam (Carpinus betulus) which is common pin in the market. PVA glue was used to make pin joints. Twenty seven treatments were obtained out of various combinations of the variables and considering four replication for each treatment, 108 H-shaped samples were prepared. The bending strength of the joints was measured. The results from mechanical test indicated that for each pin penetration depths in H joint, increasing the distance between pins, the bending strength decreased. Maximum bending strength was related to the pins having diameter of 10 millimeter. In 4d penetration depth, for each three diameters of 6, 8 and 10 millimeter, the maximum bending strength was reached on 30 millimeter intervals. The minimum bending strength for the pin having 6 millimeter diameter was obtained in the interval of 10 millimeter. The same results were obtained for the 2d and 3d penetration depths.
Research Paper
Mahid Farzi; Ali akbar Enayati; Davood Parsa paghoh
Abstract
In this investigation, soda pulps from old rags applying three pulping times (60, 120 and 180 minutes ) and three levels of active alkali ( 6,8, and 10% NaOH based on OD weight of rag) and pulping temperature of 125º C were produced. Liquor to rag ratio was kept constant at 11:1(based on the ...
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In this investigation, soda pulps from old rags applying three pulping times (60, 120 and 180 minutes ) and three levels of active alkali ( 6,8, and 10% NaOH based on OD weight of rag) and pulping temperature of 125º C were produced. Liquor to rag ratio was kept constant at 11:1(based on the weight of the rag). After pulping, hand sheets were made and then both strength and optical properties of hand sheets were measured. It was revealed that, the optimum condition for rag pulping was; 8% active alkali and 120 minutes. At this pulping conditions, the pulping yield and mechanical and optical properties of pulp were measured as yield; 86.46 %, tear index; 20.12 mN.m2/g, burst index; 2.09 kPa.m2/g, breaking length; 1.96 km, brightness; 95.86 % and opacity: 96.39
Sasan َAbangah; Ahmad Jahan Latibari; Seyad Javad Sepideh dam; Mehran Roohnia; Mohammad ali Hossein
Abstract
The influence of reinforcing fibers (old corrugated container fibers called OCC) and addition of foaming agents (Azodicarbinamide and sodium bicarbonate) on density, strength properties and dimensional stability of OCC fiber/polypropylene composite were investigated. Conten of reinforcing fibers constant ...
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The influence of reinforcing fibers (old corrugated container fibers called OCC) and addition of foaming agents (Azodicarbinamide and sodium bicarbonate) on density, strength properties and dimensional stability of OCC fiber/polypropylene composite were investigated. Conten of reinforcing fibers constant at 20% and the content of either foaming agent varied as 3, 5 and 7%. Strength properties including MOR, MOE, maximum tensile strength and modulus as well as izod impact strength were measured. Water absorption after 2 and 24 hours soaking in distilled water at 23±2 ºC were measured. Foaming agent decomposition caused some chemical residues in composite and the diffusion and penetration of polymer into the fibers structure led to increase in the density from 839.2 kg/m3 for pure polypropylene to 919.2 - 947.9kg/m3 for the composite, MOR and MOE also increased by the addition of foaming agent and the reinforcing fiber. The effect of 5 or 7% sodium bicarbonate was statistically significant and it improved the properties of the composite. Similar results were obtained for tensile strength and the modulus. Reinforcing fibers and foaming agent caused higher impact strength of the composite. Water absorption of the composites was higher than pure polypropylene.
Seyyed Khalil Hosseinihashemi; Ali Bagheri; Vahidreza Safdari; Hassan Sadeghifar
Abstract
Black locust wood is durable against microorganisms. The species is planted as a nitrogen fixing specie in many arid and semiarid areas of Iran. Extraction procedures included soaking wood samples in hexane solvent for 15 days were applied. Average percentage of black locust heartwood extractives was ...
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Black locust wood is durable against microorganisms. The species is planted as a nitrogen fixing specie in many arid and semiarid areas of Iran. Extraction procedures included soaking wood samples in hexane solvent for 15 days were applied. Average percentage of black locust heartwood extractives was determined as 8.4 percent. Identification of chemical compounds in the extractives was performed on a GC/MS device. Generally, 25 compounds were identified with different percentage in heartwood. The most abundant compound within the hexane heartwood extract of black locust samples was hexadecanoic acid as a trimethylsilyl ester, amounting to 13.39% saturated fatty acids group. The most important identified unsaturated fatty acids in the heartwood of the species 9, 12-octadecadienoic acid (Z, Z) - (10.10%). Tetradecane (6.88%) and hexadecane (6.15%) were the most important identified alkenes in the heartwood of the species. Also squalene as pure and mineral hydrocarbon oil was identified amounting to 1.17%. Squalene Vaccine manufacturers has proved that the squalene is effective against virus diseases of animals
Ahmad reza Zahedi tabarstani; Ahmad Jahan Latibari; masoudreza habibi
Abstract
Licorice root residue, a non wood lignocelullosic raw material produced following extraction process was investigated for medium density fiberboard production. MDF was produced utilizing fiber generated applying three steaming times (15, 20 and 25 minutes) at 170 °C steam temperature. ...
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Licorice root residue, a non wood lignocelullosic raw material produced following extraction process was investigated for medium density fiberboard production. MDF was produced utilizing fiber generated applying three steaming times (15, 20 and 25 minutes) at 170 °C steam temperature. The fibers were blended with 10 or 12 % urea formaldehyde resin and then the fiber mats were pressed for either 5, 6 and 7 minutes. Eighteen combinations of variables were obtained and for each combination, three boards and a total of 54 were produced. The anatomical characteristics of the roots and physical and mechanical properties of MDF including bending strength and modulus of elasticity, internal bonding and thickness swelling after 2 and 24 hours immersion in water were measured. The results revealed that the average fiber length and diameter of the root fibers were 1.02 mm and 11.63 µm respectively. The maximum bending strength , modulus of elasticity, internal bonding of the boards produced using fibers generated after 20 minutes steaming time, 7 minutes pressing and 10% resin were measured as 5.291 MPa. 559.4 MPa. and 0.1245 MPa., respectively. The minimum thickness swelling after 2 and 24 hours immersion in water of the above mentioned boards were 31.6% and 34.12% respectively. The results indicated that the fiber produced from licorice root can be used as a partial substitute in MDF production.
Abolfazl Kargarfard
Abstract
The purpose of this study was to utilize rose flower stem residues in the core layer of particleboard. Three press temperatures of 160, 170 and 180 C and five percentages of rose stem pruning (0, 25, 50, 75 and 100%) in the core layer were used in the production of poplar wood particleboard. Mechanical ...
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The purpose of this study was to utilize rose flower stem residues in the core layer of particleboard. Three press temperatures of 160, 170 and 180 C and five percentages of rose stem pruning (0, 25, 50, 75 and 100%) in the core layer were used in the production of poplar wood particleboard. Mechanical and physical properties were measured and analyzed applying factorial experiment and complete randomized design.The results indicated that modulus of rupture (MOR) and modulus of elasticity (MOE) of the boards significantly decreased by increasing rose stem particles in the core layer and press temperature did not show any significant effect on MOR and MOE of the boards. However, the addition of rose stem particles in the core layer deteriorated the IB of the boards and the lowest value was attributed to 100% stem residues in core layer. Also, by increasing of rose stem particles in core layer, thickness swelling after 24 hours immersion in water increased significantly and showed irreversible behavior to IB of the boards. The results showed that the incorporation of this residues to particleboard furnish will not reduce the properties of the board and it met the standard requirements. Our finding confirmed that agricultural residues can be used in combination with conventional raw materials in particleboard production.
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.
Research Paper
Fatemeh Bvanaghi; Maryam Ghorbani; Abolfazl Kargarfard
Abstract
Effects of acetylation and press time on heat transfer to the core layer of particleboard mat in hot pressing were investigated. Particleboard was made using hornbeam particles. Particles were soaked in acetic anhydride for 24 hours to reach three degrees of acetylation (8, 12 and 17%). The treated particles ...
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Effects of acetylation and press time on heat transfer to the core layer of particleboard mat in hot pressing were investigated. Particleboard was made using hornbeam particles. Particles were soaked in acetic anhydride for 24 hours to reach three degrees of acetylation (8, 12 and 17%). The treated particles were heated by oven at 120°C for 40, 180 and 360 minutes, respectively. Acetylated and non-treated (control) particle were blended with 10% melamine urea formaldehyde (based on the oven-dry weight of particles) and and then pressed to make boards. During pressing operation of particle mat, heat transfer to the middle layer of the mat was measured by a Cr- Ni wires thermocouple. Three press times (5, 6 and 7 minutes) were used in the manufacturing process. Results showed that increasing the degrees of acetylation, heat transfer decreased. In control samples and in low-degree modification (8%), in the early period, core temperature reached 100°C. At 12%, after 390 seconds and at the highest degree (17%) even in the longer press time (7min), the core layer temperature did not reach to 100°C.
Research Paper
Alireza Asgari; Ahmad Jahan latibari; Seiad Javad Sepidedam
Abstract
The impact of Multi Wall Carbon Nano Tubes addition on mechanical properties, water absorption and thickness swelling of polypropylene/old corrugated container (OCC) fiber composites was investigated. Polypropylene/ OCC fiber composite was prepared using 30% OCC fiber, 67% polypropylene and 3% MAPP. ...
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The impact of Multi Wall Carbon Nano Tubes addition on mechanical properties, water absorption and thickness swelling of polypropylene/old corrugated container (OCC) fiber composites was investigated. Polypropylene/ OCC fiber composite was prepared using 30% OCC fiber, 67% polypropylene and 3% MAPP. Three levels of multi wall carbon nano tubes (1, 2, 4% based on the weight of fiber/polypropylene/MAPP mixture) were added. Composite compound was prepared using a Haake mixer and the test samples were extruded. The results of strength measurement indicated that when 1 or 2% multi wall carbon nanotubes were added, Izod impact strength and flexural strength improved. Higher flexural modulus of elasticity was reached as either 2 or 4% multi wall carbon nano tubes was added. The performance of 4% multi wall carbon nano tubes on flexural modulus of elasticity was superior. Lower water absorption and thickness swelling levels were observed, as 1% multi wall carbon nano tubes was added.
Research Paper
amir lashgari; Peyman Sinambari
Abstract
Effects of screw length (2, 2.5,3 inch), wood species (beech, alder, white spruce), and two screw interval (2, 2/5 cm) on bending strength of the T-type joints were investigated. In order to fabricate the T –shaped joints, dimensions of the parts were determined as 15*5/5*2/5 cm. From the ...
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Effects of screw length (2, 2.5,3 inch), wood species (beech, alder, white spruce), and two screw interval (2, 2/5 cm) on bending strength of the T-type joints were investigated. In order to fabricate the T –shaped joints, dimensions of the parts were determined as 15*5/5*2/5 cm. From the above variables, 18 combinations were reached. Four replications, and a total of 72 specimens were made and the mechanical strength of the specimens were measured by mechanical testing machine. Results indicated that the beech joints with 3-inch length screws had the highest bending strength, while the lowest bending strength was observed in spruce wood with 2-inch length screws. The study revealed statistically significant differences between the wood species, while there were not any difference between screw interval and bending resistance.
Saeid Kamrani; Ahmad reza Saraeian; Hossein Resalati; Ali Ghasemian
Abstract
The main objective of this study was to determine the trends of fiber dimension variation along the longitudinal direction of wheat straw as a criteria for papermaking. Zagross wheat straw was collected from the agricultural and natural resources research center, Golestan province .The fiber biometric ...
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The main objective of this study was to determine the trends of fiber dimension variation along the longitudinal direction of wheat straw as a criteria for papermaking. Zagross wheat straw was collected from the agricultural and natural resources research center, Golestan province .The fiber biometric characteristics including fiber length, fiber diameter, lumen diameter and cell wall thickness in three internodes were determined .Results showed that, the difference in fiber diameter, lumen diameter and cell wall thickness were sttistically significant between three internodes of wheat straw at 99% confident Based on the computed papermaking indices (flexibility ,softness and runkle number), it was predicted that the papers produced from the first and the third internode of wheat straw may have higher tensile,folding and burst strength and the papers produced from the second internode may have higher tear strength.
Jafar Azimvand; Seeyed Ahmad Mirshokraie; Ali Abdolkhani
Abstract
In this study, the chemical changes of functional groups (C=O) and double bond (C=C), induced in the structures of poplar kraft lignin and bagasse soda lignin were investigated. The reducing effect of sodium borohydride and sodium hydrosulfite, followed by the UV irradiation on these two compounds were ...
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In this study, the chemical changes of functional groups (C=O) and double bond (C=C), induced in the structures of poplar kraft lignin and bagasse soda lignin were investigated. The reducing effect of sodium borohydride and sodium hydrosulfite, followed by the UV irradiation on these two compounds were determined using FT-IR spectroscopy. Results showed that, reduction of the lignin by reducing chemical imparted stability in lignin structure against UV light. The FT-IR spectroscopy showed that, the major light stabilizing phenomenon that is responsible for this stability is the conversion of carbonyl groups (C=O) alcohol group (C-OH) and double bonds (C=C) to single bonds (C-C). Between the two reducing compound, sodium borohydride showed better performance than sodium hydrosulfite.
