Research Paper
Pulp and paper
Maryam Alipoor; Ghasem Asadpur Atouei; Seaid Majid Zabihzadeh; Zohreh Ghazvini
Abstract
With considering that in chemical-mechanical pulp (CMP) production process , the wood chips washing pre-treatment is important , so this research was conducted to investigate the effect of pre-treatment washing of populous deltoids wood chips on CMP Optical(brightness and opacity) and Strength(tensile ...
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With considering that in chemical-mechanical pulp (CMP) production process , the wood chips washing pre-treatment is important , so this research was conducted to investigate the effect of pre-treatment washing of populous deltoids wood chips on CMP Optical(brightness and opacity) and Strength(tensile and burst indexes) properties. Pre-treatment was accomplished with pure hot water and alkaline solutions (NaOH) at three levels of 0.5, 2 and 3.5 percent too. Pre-treated populous deltoids wood chips and control (chips without washing) were converted to pulp by CMP process. The results of this research indicated that the pretreatment of populous deltoids wood chips with hot water and also alkaline solutions caused wood chips mass and using of these treated chips for pulping caused pulp yield and brightness increscent, pulp strength reduction and also energy consumption increscent. . Removing of some part of chips hemicellulos have negative effect on the pulp refinability and cause pulp strength reduction.
Research Paper
Physics and Mechanical Wood
Hamid Reza Koohkan; Ali Maleki; Shahin Besharati
Abstract
In this research the effects of moisture content and cutting speed on the specific shearing energy and shearing stress for four variety of almond tree (Mamayy, Rabi, Sefid and Shahrodi12) was investigated and results the each any the varieties were compared with each other. Shear properties of almond ...
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In this research the effects of moisture content and cutting speed on the specific shearing energy and shearing stress for four variety of almond tree (Mamayy, Rabi, Sefid and Shahrodi12) was investigated and results the each any the varieties were compared with each other. Shear properties of almond wood varieties in this study, using a universal testing machine manufactured STM20 Sntam was determined. Knife bevel form of one-sided and edge angle is 40 degree.The characteristics at three moisture levels of 18, 25 and 45% (w.b.) wet basis, three cutting speed levels of 20, 30 and 40 mm/min and in three size 6, 9 and 12 mm were determined. The results of analysis of variance (ANOVA) showed specific shearing energy and shearing stress to all test factors were response significant (P<0.01). The results showed that Both specific shearing energy and shearing stress increased with an increase in moisture content. While increasing cutting speed of 20 to 40 mm per minute, these values are reduced. Based on the results of the study the average specific shearing energy were determined for varieties Mamayy, Rabi, Sefid and Shahrodi12 59.41, 56.088, 54.38 and 77.57 J/ mm2 respectively and for shearing stress, 16.01, 14.34, 13.73 and 19.35 MPa, respectively. Also, the study effect of test factor in the shear test results can be explained factors moisture content and variety most effect and relatively less effect in cutting speed factor.
Research Paper
Pulp and paper
Hamid reza Rudi; Morteza Nazeryan
Abstract
In this study, the effect of using Layer-by-Layer (LbL) treated pulp as mixed with refined OCC recycled pulp was investigated on paper physical properties. The LbL treatments were conducted to build 7 consecutive cationic and anionic starch layers. Afterwards, at three levels of 10, 20 and 30 percent, ...
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In this study, the effect of using Layer-by-Layer (LbL) treated pulp as mixed with refined OCC recycled pulp was investigated on paper physical properties. The LbL treatments were conducted to build 7 consecutive cationic and anionic starch layers. Afterwards, at three levels of 10, 20 and 30 percent, LbL-treated pulp was added to the 10, 15 and 20 minutes refined pulp. From mixed pulp, handsheets with basis weight of 60 g/m2 were prepared and its physical properties including: thickness, density, roughness and formation was examined. The results of LbL treatment using AFM micrographs indicated that the surface of fibers was covered with starch polymer particles by means of Layer-by-Layer treatment. Also, SEM micrographs confirm starch impregnated fibers surface and formation of rough surfaces. Analysis mutual effect of independent variables revealed that addition of LbL-treated pulp to the refined recycled pulp had only significant effect on paper thickness and surface roughness, while variation of refining time had significant influence on all physical properties. In current research, considering the results of ANOVA test and the mutual effect of the content of LbL-treated pulp and different refining time levels on the paper physical properties using response surface methodology, adding of 10 % of LbL-treated pulp to the OCC pulp and applying the refining time of about 18.66 minutes was selected as optimum condition.
Research Paper
Chemistry of wood
Asghar Tabei
Abstract
In this study, changes in optical behavior of Poplar Kraft lignin before and after methylation by using dimethyl sulphate, was monitored by measuring optical indices ( brightness,light absorbtion coefficient, light scattering coefficient,light absorbtion coefficient to light scattering coefficient ratio ...
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In this study, changes in optical behavior of Poplar Kraft lignin before and after methylation by using dimethyl sulphate, was monitored by measuring optical indices ( brightness,light absorbtion coefficient, light scattering coefficient,light absorbtion coefficient to light scattering coefficient ratio and Post-Color numbers) of impregnated papers following accelerated photo aging. The structural changes in lignin caused by methylation reaction, were verified by using fourier transform infar red( FT-IR) spectroscopy. The results showed that, by methylation of lignin, it was observed that, in methylated lignin-containing papers, the extent and stability of brightness is more and post- color number is less compared to control samples. In methylated samples, even the strange phenomenon of photo bleaching was observed. Therefore, it was found that, methylation of lignin can prevent the formation of quinone groups and increases the stability of the optical indices in the photo aging conditions.Keywords: Kraft lignin, methylation treatment, accelerated photo- aging, optical indices,lignin-containing papers.
Research Paper
Composite wood products
Vahid Tazakor Rezaie; abdolah Najafi; Ahmad Sinaie
Abstract
In this study, effect of nano-wollastonite on fire resistance characteristics of wood flour/polypropylene composite was investigated. The composites samples were manufactured using a dry blend/hot press method. In this study, the dried wood flour of beech as the filler in a 60%, poly propylene as the ...
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In this study, effect of nano-wollastonite on fire resistance characteristics of wood flour/polypropylene composite was investigated. The composites samples were manufactured using a dry blend/hot press method. In this study, the dried wood flour of beech as the filler in a 60%, poly propylene as the matrix in a 37% and polyethylene grafted with maleic anhydride as the coupling agent in a 3% total weight was used. Also, nano-wollastonite was used in four levels of dried wood flour loading (0, 1, 3 and 5%). Nominal density and dimensions of the composites were 1 g/cm3 and 1*20*25 cm, respectively.Bending strenght according to ASTM standard and Fire resistance characteristics such as, flammability duration, duration of flame after removing the burner, duration of glow after removing the burner and mass reduction were measured acceding to ISO 11925. Results indicated that by increasing the nano-wollastonite increases the bending strengh,MOE and flammability duration increased but mass reduction, duration of flame and duration of glow decreased. Also the dispersion of nano-wollastonite in composites was evaluated by Filed Emission Scanning Electron Microscopy (FE-SEM).
Research Paper
Physics and Mechanical Wood
Aysoda Talaei; Mohammad saleh Zare; Hamideh Abdolzadeh
Abstract
The aim of this study was to investigate the effects of furfurylation on shear strength of bond line and screw withdrawal resistance of beech (Fagus orientalis) and fir (Abies alba) species. In this regard, specimens with two different values of furfurylation i.e. low (fir 14% and beech 20%) and high ...
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The aim of this study was to investigate the effects of furfurylation on shear strength of bond line and screw withdrawal resistance of beech (Fagus orientalis) and fir (Abies alba) species. In this regard, specimens with two different values of furfurylation i.e. low (fir 14% and beech 20%) and high (fir 38% and beech 65%) levels were prepared and evaluated in comparison with untreated specimens. The furfurylation was performed after impregnating the specimens by furfuryl alcohol under vacuum condition followed by heating duration to complete polymerization and crosslinking. Specimens were prepared according to standard ASTM D 905 in order to assess shear strength of bond line formed with three different types of adhesives, single-component polyurethane, polyvinyl acetate as well as urea-formaldehyde. Also screw withdrawal resistance of wood polymer specimens was measured perpendicular to grain and parallel to grain. The results indicated that the shear strength of the bond line decreased and screw withdrawal resistance increased by furfurylation level. Examination of adhesion mechanism demonstrated that formation of an appropriate interface between water-soluble adhesives and wood-polymer involves effective penetration of adhesive into cell wall. Hence, the interface of adhesives and material would be the determining factor in developing strength of adhesive joints. Since the wood-furfuryl alcohol is a cell-wall wood-polymer, the possibility of creating an appropriate interface by increasing of furfurylation level was impaired. On the other hand, the adhesion mechanism of polyurethane glue compared to water-soluble adhesives such as polyvinyl acetate and urea-formaldehyde is significantly different, therefore exhibited more strength. The withdrawal screw resistance of furfurylated wood was increased by furfurylation level due to changing nature of wood and increasing shear strength of wood-polymer. This gain was also more evident in fir than beech. The results showed that screw withdrawal resistance perpendicular to grain was higher than parallel to grain.
Research Paper
Pulp and paper
Mohammad Azadfallah; Hamid Khodabandehlo; Amirabas Shaygani Akmal
Abstract
The oil-impregnated dielectric papers are the main components of distribution transformer which govern its service time. Therefore, durability enhancement of this grade of paper will cause to extend transformers life. Hence in this research long fiber unbleached Kraft pulp and mixture of it with bagasse ...
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The oil-impregnated dielectric papers are the main components of distribution transformer which govern its service time. Therefore, durability enhancement of this grade of paper will cause to extend transformers life. Hence in this research long fiber unbleached Kraft pulp and mixture of it with bagasse soda pulp with the ratio of 20% to 80% were used to make oil-impregnated dielectric papers with the grammage of 60 g/m2. The effect of dicyandiamide application with different content in paper structure and thermal aging were then assessed on dielectric properties and tensile strength of the insulation papers. The results showed that with increasing dicyandiamide content, the capacitance and tensile strength index decreased in comparison with untreated samples, but dielectric loss, insulation resistance, and breakdown voltage were improved. However, slight changes were observed in most dielectric properties during aging, but dicyandiamide caused to prevent loss of the tensile strength of insulated papers. Generally it could be concluded that dicyandiamide acts efficiently in thermal stabilization of insulation paper exposed to aggressive conditions inside the oil-filled transformer.
Research Paper
Management and Economics wood
Farvahl Sobhani Oskouie; Maryam Ghorbani; Saeid mojtaba Amini nasab
Abstract
The objectives of this research determine for optimum condition modification with effect of 3-(trimethoxysilyl) propyl methacrylate on physical properties of Poplar wood-polymer were performed. Test samples from Poplar species were divided to five levels: control, Acidified Ethanol/Silan/110 ˚C, Acidified ...
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The objectives of this research determine for optimum condition modification with effect of 3-(trimethoxysilyl) propyl methacrylate on physical properties of Poplar wood-polymer were performed. Test samples from Poplar species were divided to five levels: control, Acidified Ethanol/Silan/110 ˚C, Acidified Ethanol/Silan/150 ˚C, Ethanol / Silan / 150°C and Silan/150°C in two levels with and without Benzoyl peroxide. Samples were impregnated with silan compound according to vacuum-pressure method in experimental cylinder. Weight percent gain of Silan/Et/BP/150 ˚C level by 24/40% had the maximum value were determined. Bulking efficiency and OH groups substituted in Silan/AEt/150 level with 6.81 % and 1.10 mol/gr, respectively compared with the other levels.Modification were resulted to improve water absorption and dimensional stability that maximum dimensional stability in contain initiator level were determined. In immersion-dry period test, the highest and lowest bulking efficiency in Silan/AEt/150 and Silan/Et/150 were reported. Maximum of weight loss in immersion-dry test was determined in Silan/AEt/110 with the 3.6% value.Key words: physical properties, 3-(trimethoxysilyl) propyl methacrylate, Asidified Ethanol, bulking efficiency
Research Paper
asghar tarmian; Seaid Alireza Dehghan; Elnaz Trighnoor; Mohammad reza Pyramon; Razyeh Shamsy; Mohammad Layeghi
Abstract
In this research, the performance of a semi-greenhouse solar kiln was evaluated for dying different wood species in different season in Karaj. This study was carried out in two separate parts. In the first part, the flat-sawn boards of oak and fir with a nominal thickness of 50 mm were dried during summer ...
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In this research, the performance of a semi-greenhouse solar kiln was evaluated for dying different wood species in different season in Karaj. This study was carried out in two separate parts. In the first part, the flat-sawn boards of oak and fir with a nominal thickness of 50 mm were dried during summer of the year 2012. In the second part, the flat-sawn boards of beech and poplar with the same thickness were dried in autumn, 2014 and spring, 2015. For both parts, the boards were also air-dried. The temperature measured inside the solar kiln was 35 ºC greater than that outside during daytime and also the kiln temperature ranged from 55 to 75ºC during 10 a.m. to 2 p.m.. In both parts of research, all wood species dried in the solar kiln faster with better quality compared to those air-dried. The severity of casehardening and surface checking in the boards dried in the solar kiln was lower and more homogenous moisture profile was observed. In addition, the final moisture content was lower for the boards dried in the solar kiln.
Research Paper
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.
Research Paper
Composite wood products
Samira Brzali; Laya Jamalirad; Farshid Faraji; Sahab Hejazi
Abstract
In this research with the aim of using a natural component, renewable and environmentally friendly which is not environmental pollution, the physical and mechanical properties of plywood manufactured by populous with urea formaldehyde resin and silk cocoon were studied. For this purpose, silk cocoon ...
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In this research with the aim of using a natural component, renewable and environmentally friendly which is not environmental pollution, the physical and mechanical properties of plywood manufactured by populous with urea formaldehyde resin and silk cocoon were studied. For this purpose, silk cocoon was used as filler and reinforcement for four levels of 0, 10, 20 and 30 percent according to dry weight of urea formaldehyde resin. The physical and mechanical properties of samples including water absorption and thickness swelling after 2 and 24 hours immersion in water, bending strength parallel and perpendicular to the surface layer grain and shear strength were measured. The results show that increasing the amount of silk cocoon, decreased water absorption and thickness swelling after 2 and 24 hours immersion in water and increased bending strength parallel and perpendicular to the surface layer grain and shear strength. So that, using 30 percent of silk cocoon, dimensional stability, bending strength and shear strength, were improved.
Research Paper
Pulp and paper
Mohtaba Goli; Majid Zabihzadeh; Saeed Mahdavi; Hassan Sadeghifar
Abstract
The objective of this study was determination of the best method of bleaching including refining and bleaching (RB) or bleaching and then refining (BR) on chemical mechanical pulp (CMP) for the production of newsprint. Wood raw material consists of mixed wood forest species was chipped and air dried ...
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The objective of this study was determination of the best method of bleaching including refining and bleaching (RB) or bleaching and then refining (BR) on chemical mechanical pulp (CMP) for the production of newsprint. Wood raw material consists of mixed wood forest species was chipped and air dried to calculate the moisture content. Wood composition percentages for CMP pulping was 40% poplar, 30% maple, 7.5% oak, 7.5% alder, 7.5% willow, and 7.5% Persimmon. In order to remove heavy metal ions of pulp, the chelating was carried out with DTPA. TCF Bleaching carried out by 3% H2O2 and 2.5% NaOH based on dry weight of pulp with initial brightness of 44.6% ISO. Pulp bleaching was done in two stages, before and after the refining by laboratory PFI mill beater. Finally, handsheets were made from the RB and BR treated pulps and the sheet properties were evaluated according to TAPPI test methods. The results showed that BR treatment increased tensile, burst, tear indices, brightness, scattering coefficient, and density, but reduced yellowing, opacity, and light absorption coefficient. The results confirmed the conventional method of CMP pulp treatment (BR) in MWPI.
Research Paper
Management and Economics wood
Aboalhassan hosseini; Mohammad reza Tabibi; Seaid ali Hosseini
Abstract
In this study, the effect of "aligning marketing strategy" on "supply chain performance" and "organizational performance" in office furniture companies was taken into account. The study population was firms where based in the industrial towns, Tehran, such as Chahardangeh, Khavaran and Parand. At last, ...
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In this study, the effect of "aligning marketing strategy" on "supply chain performance" and "organizational performance" in office furniture companies was taken into account. The study population was firms where based in the industrial towns, Tehran, such as Chahardangeh, Khavaran and Parand. At last, 206 samples were collected. This is, based on purpose, an applied research, however, it is a descriptive survey in terms of data collection. For analyzing of hypotheses and research questions, "structural equation modeling" was used. According to the results, the impact of aligning marketing strategies on the value of supply chain in office furniture firms was determined 7.45 at 95% confidence level and also the effect of the value of supply chain on organizational performance was gained 4.19 at the same confidence level. Both indicated the relationships in hypotheses were significant. From this research, it was concluded that aligning marketing strategies had improved organizational performance directly and increased the value of supply chain indirectly in active companies in the office furniture industry which helped to improve "organizational performance".
