Management and Economics wood
abdollah zamnai; Mohammad reza Mastari farahani
Abstract
In this research, the effect of oil heat-treated on the outdoor performance of coatings namely, transparent resin stain, alkydi paint, semi- transparent cellulosic stian, acrylic paint coated on eastern cotton wood was investigated. For this purpose, sound specimens with the dimensions of 50×50×2 ...
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In this research, the effect of oil heat-treated on the outdoor performance of coatings namely, transparent resin stain, alkydi paint, semi- transparent cellulosic stian, acrylic paint coated on eastern cotton wood was investigated. For this purpose, sound specimens with the dimensions of 50×50×2 mm (Longitudinal × tangential × radial) were prepared from sapwood. Test samples were treated with canola oil at temperatures of 180, 200 and 220 ° C for 4 hours. The coatings were the wet film thickness of 150µm were applied on the specimens using an applicator. The coating adhesion was measured according to ASTM D 4541 standard, and the color characteristics of the coating were measured according to ASTM D 2244 before and after a natural weathering for 180 days. The statistical analysis of the color change data showed that the effect of the oil heat-treatment on the color change depended on coating type. The statistical analysis of the adhesion strength data showed that the adhesion strength depended on the combination of weathering, oil heat-treatment and coating type.
Management and Economics wood
Saeed Hasani; Seid Khalil Hosseini Hashemi; Ramin Farsi; Ahmad Jahan Latibari
Abstract
AbstractAmong the forest diseases, fungi are the most important factors that cause irreparable losses to the wood in standing trees and logs. Fungi are the cause of contamination and decay of trees and timbers in forest or in the stock of factories. Decayed woods are one of the biomass resources and ...
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AbstractAmong the forest diseases, fungi are the most important factors that cause irreparable losses to the wood in standing trees and logs. Fungi are the cause of contamination and decay of trees and timbers in forest or in the stock of factories. Decayed woods are one of the biomass resources and a great amount of decayed woods in the forests are not viable. In this study some experiments were conducted in order to investigate the effect of Coriolus versicolor decay on compounds obtained from beech wood (Fagus orientalis L.) pyrolysis and preparation of various and valuable chemicals. Separation and identification of chemical compounds in sound wood and decayed wood of beech was conducted by using pyrolysis method at 500° C and in nitrogen atmosphere. Separation and identification of extracted chemical compounds was carried out using sailylation of these compounds by N, O-bis (trimethylsilyl) trifluoroacetamide and also using Gas Chromatography and Mass Spectrometry method. Totally, 23 compounds were identified in sound beech wood which most of these compounds, in this temperature, are related to 2,6-dimethoxyphenol and 3-hidroxy-4-methoxy benzoic acid; and 31 compounds were detected in decayed beech wood that most of them are related to Cyclononasiloxane octadecamethy and 4-(3,4-Dimethoxybenzylidene)-1-(4-nitrophenyl) and also 17 compounds were detected the same in sound and decayed wood.
Management and Economics wood
Reza Oladi; Saeideh Nasiriani; Afshin Danekar
Abstract
From a long time ago, researchers in the fields of wood science, dendroclimatology and tree physiology were interested in variation of tree-ring width and vessel features within a tree. However, mutual relationship and interplay between these anatomical features were less studied. In this regard, the ...
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From a long time ago, researchers in the fields of wood science, dendroclimatology and tree physiology were interested in variation of tree-ring width and vessel features within a tree. However, mutual relationship and interplay between these anatomical features were less studied. In this regard, the main question is whether the pattern of adjustment in wood anatomical traits (tree-ring width and vessel features) is similar in all hardwoods and in every site? Or may the same species chose different strategies in different sites? To answer these questions, two growing sites of black alder (Alnus glutinosa) with completely different micro-climates (dry and brackish) were selected near Astara city. In each site, a few trees were selected, cut or cored. After preliminary treatments, wood cross sections were prepared from the bark to the pith of each tree. These sections were scanned and by using an image analysis software, tree-ring width (TRW), average vessel lumen area (AVLA), number of vessel in the unite of an area (VF), and the porosity (Porosity) of a tree ring were measured in the last 20 annual rings of each tree. To study the inter-relations between variables at each site, they were analyzed using different statistical tests. The results showed that the inter- and mutual-relations between tree-ring width and vessel features were similar in tow studied sites. In brief, it can be concluded that regardless of site and climatic condition, in alder trees, wider tree rings leads to fewer vessels and these two anatomical traits are controlled by the same component but AVLA is affected by a different component and is not associated with the tree-ring width.
Management and Economics wood
Elham Hatamzadeh; Maryam Ghorbani; Poria bi parva
Abstract
In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according ...
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In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according to ASTM-D4446-05, and divided to three levels; control, Zncl2/NH3 and Zncl2/Naoh at 0.05M concentration and pH=10. Test samples were impregnated with salty precursor in the experimental cylinder using vacuum-pressure method, and in order to adjust the pH, soda and ammonia added. Due to the electron microscope images, change the type of precursor deposition, caused the different structure of ZnO nanoparticle. Retention of zinc oxide nanoparticles, density changes, water absorption, swelling and anti-swelling efficiency (ASE) were determined after synthesis. Retention of zinc chloride precursor with ammonia and soda acidity regulator was determined 4.43 and 1.71kg/m3 respectively. Water absorption increased at first hours of immersion, and then decreased. These treatments increased water absorption of wood. Least swelling and water absorption, and maximum ASE were measured in Zncl2/NH3 level.
Management and Economics wood
Asghar Sobhi Nosrat; Ajang Tajdini; Shademan Pourmousa
Abstract
In this research by using the professors and specialists ideas and studying the related papers, the effective factors of relations between companies and industrial suppliers were identified and satisfaction concept in the supply chain was measured with investigating trust‚ relation‚ cooperation ...
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In this research by using the professors and specialists ideas and studying the related papers, the effective factors of relations between companies and industrial suppliers were identified and satisfaction concept in the supply chain was measured with investigating trust‚ relation‚ cooperation ‚ accordance with expectations ‚ quality ‚ cost and material provision time and production ‚ order time ‚ and delivery time until transferring to the final costumer variables. Statistics population of the research was considered ‚ all of managers of the companies and raw material suppliers which are active in the home wooden industry of Tehran province in the field of furniture ‚ and considered data were collected by using questionnaire .The research method is based on goal ‚ is applied form and according to implementation way and data collection is correlation description. We have used frequency distribution tables for findings description. In the inference step ‚ we have used spearman correlation tests and path analysis with the help of SPSS16 software. The seven hypothesis are used which one of them was omitted in the analysis step and from six hypotheses which were used, one of them was not accepted. The research results showed that there are significant and heavy relationships between trust ‚ relation and cooperation and cost variables and industrial buyers’ satisfaction. In the case of the time delivery speed, although there is relationship but it isn’t high correlation
Management and Economics wood
Azadeh Nikkhah Shahmirzadi; Maryam Ghorbani; Seyed Mojtaba Amininsab
Abstract
This research was conducted to investigate the effect of modification with maleic anhydride and methyl methacrylate on mechanical properties and decay resistance of poplar wood. Samples of mechanical and biological resistance tests were prepared according to ASTM D143-94 and EN113 standards. Treatment ...
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This research was conducted to investigate the effect of modification with maleic anhydride and methyl methacrylate on mechanical properties and decay resistance of poplar wood. Samples of mechanical and biological resistance tests were prepared according to ASTM D143-94 and EN113 standards. Treatment levels were divided into 4 groups; control, methyl methacrylate, maleic anhydride and combined of maleic anhydride/ methyl methacrylate. Samples were impregnated with maleic anhydride and monomer using vacuum- pressure method with experimental cylinder. Maleic anhydride treated samples were heated in oven for 4 and 24 hours at 150 and 103ºC. For polymerization, methyl methacrylate monomer treated samples were heated in oven at 90ºC for 24 hours, consequently at 103ºC for the same time. Methyl methacrylate polymer coating formed on the cell wall, causing 22.57% improvement in the lateral stability under pressure parallel to grain. Highest value in modules of rupture, elasticity and hardness were measured in combined level with 24.13, 47.13 and 45.53% improvement compared with the control, respectively. Maleic anhydride in the presence of methyl methacrylate, with decreasing polarity of the wood and create a good distribution of the particle and the polymer, resulting in the cross linking formation and transmission of uniform tension that would lead to improved mechanical properties. Also, decay resistance was improved in all levels of modification, so that weight loss declined from 80.4% in control to 4.29% in combined level. Modified with maleic anhydride because of the wood composition change, reduction in moisture absorption ability of cell wall and bulking effect, and the presence of methyl methacrylate in the cell cavities as a physical barrier to the movement of fungi mycelium and moisture, were leading to improved decay resistance.
Management and Economics wood
Mohammad Saleh Hosseini Fard; Saeed Khojasteh Khosro; Behbod Mohebby
Abstract
In this research the effect of oil-heat treatment of Fir species (Abies spp) on contact angle and adhesion strength of organic solvent based and water based coating (acid catalyzed and acrylic water based coating) were investigated. Soy oil was used for the heat treatment modification. Modification process ...
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In this research the effect of oil-heat treatment of Fir species (Abies spp) on contact angle and adhesion strength of organic solvent based and water based coating (acid catalyzed and acrylic water based coating) were investigated. Soy oil was used for the heat treatment modification. Modification process of samples were done at two time, 12 and 15 hours with temperature of 180°C. Control and modified samples were covered with acid catalyzed and acrylic water based coating. Contact angle of water was measured before and after treatment. Adhesion strength of coating was determined according to ASTM 4541 standard. Obtained results of contact angle and adhesion strength were compared with the control samples. The results showed that modification process of oil-heat treatment increased contact angle. This increase continued by increasing treatment time. Increasing contact angle reduced wettability of samples’ surface. On the other hand oil-heat treatment of wood, decreased adhesion strength of coating. The lowest value of adhesion strength was observed in the modification process of 15 hours. Results of comparing coating revealed that acid catalyzed coating had higher adhesion strength than acrylic water based coating but generally no significant differences was observed between these coating.
Physics and anatomy
vahidreza safdari; shadman Pourmosa
Abstract
The Avicennia tree genus was named in honor of Ibn Sina, a 10th century Persian philosopher and physician known more commonly as Avicenna. In this paper wood anatomical property of Avicennia marina (Acanthaceae) which is one of the most important species of Iranian Mangrove forest has been investigated. ...
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The Avicennia tree genus was named in honor of Ibn Sina, a 10th century Persian philosopher and physician known more commonly as Avicenna. In this paper wood anatomical property of Avicennia marina (Acanthaceae) which is one of the most important species of Iranian Mangrove forest has been investigated. Wood samples were taken from trunk of three adult trees, and and micro -sectioned and dyed by Astrablue and Safranin O and finally mounted by Canada balsam. Also Wood chips (match size) were placed in equal parts of glacial acetic acid and hydrogen peroxide and were put in the oven at 60°C for 48 hours, then counted and stained on microscope slides. The presence of concentric included phloem which is surrounded by lignified conjunctive parenchyma (axial parenchyma) and scleroid bands are the most important anatomical characteristics of Avicenna marina. The variability of anatomical characteristics of Avicennia marina in different references can be attributed to grwoing site condition (altitude and latitude).
Chemistry of wood
milad tajik; ramin vaysi; majid kiaei
Abstract
This research was carried out to identification and comparison of organically chemical component in the wood / bark extractives Eucalyptus camaldulensis. Three healthy trees were cut down from Nowshahr forest and samples were converted into the wood flour. The extractives was prepared with acetone solvent ...
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This research was carried out to identification and comparison of organically chemical component in the wood / bark extractives Eucalyptus camaldulensis. Three healthy trees were cut down from Nowshahr forest and samples were converted into the wood flour. The extractives was prepared with acetone solvent according to TAPPI standard, then transfer to the ballon and then the BSTFA catalyst was added and transfer to the GC / MS injections. Identification of components was done according to the retention time curve, calculation of Kovats correlation and Adams table. Out of 13 components in the bark of Eucalyptus and 18 components in that wood, 2 constituents such as Bis (2 - ethyl hexyl) phthalate and hexadecanoic acid was detected as the same. The most important of chemical component in the bark is (2 _ ethyl hexyl) phthalate (98.72 %). 2 - Pentanone (57.41 %) was important component in the eucalyptus wood .
Management and Economics wood
Reza Hajihassani; seyedeh masoomeh
Abstract
Abstract In this research, the effects of acetylation on the prevention of white-rot and brown-rot fungi deterioration in medium density fiberboard (MDF) were investigated. Sample boards were made from acetylated poplar fibers, which were treated at different times (0, 30, 90 and 270 minutes) to obtain ...
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Abstract In this research, the effects of acetylation on the prevention of white-rot and brown-rot fungi deterioration in medium density fiberboard (MDF) were investigated. Sample boards were made from acetylated poplar fibers, which were treated at different times (0, 30, 90 and 270 minutes) to obtain different weight percent gains (WPGs of 0, 4.85, 9.1, and 15.8 %). Totally twelve samples boards at three replication for every treatment were made.. The results were analyzed based on a complete randomized design (CRD) under a factorial experiment. Results revealed that the acetylation decreased the deterioration effect of white-rot and brown-rot fungi. As it was determined, the weight reduction of acetylated boards with the highest WPG (15.8 %) after 16 weeks were measured as 1.605 % and 16.93 % for white and brown-rot fungi, respectively. It was also determined that the weight loss of the control (untreated boards) samples was measured as 39.96 and 49.31% in the same period. The research results showed that the acetylation enhances biologic resistance in medium density fiberboard.
Management and Economics wood
Aliakbar Aenayati; Hamid Hatefnia
Abstract
Microbiological degradation of wood and wood products is one of the most important of disadvantage which reduce its useful life. There are various methods to increase the natural durability of wood and wood products and most of them using chemical reagents. In the past, the thermal ...
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Microbiological degradation of wood and wood products is one of the most important of disadvantage which reduce its useful life. There are various methods to increase the natural durability of wood and wood products and most of them using chemical reagents. In the past, the thermal modification has been used as a ecofriendly method in many times. In this research the effects of steam pretreatment on the fungal durability of particleboard were studied. Steam pre-treatment was applied on the poplar wood particles using a stainless steel reactor at four temperature levels (155, 165, 175 and 185 ºc) and three retention times (15, 30 and 45 min). The amount of hemicelluloses, acetone extractives of wood particles as well as EMC and Mass loss of test panels were measured.The results indicated that the steam pretreatment significantly decreased the amount of hemicelluloses of wood particles, EMC and mass loss of test samples where as the amount of extractives of wood particles increased.According to the results, the variation of Mass loss of particleboard test samples showed a significant correlation to the variation of EMC of test samples, hemicelluloses and extractives amount of wood particles when the wood particles thermally pre-treated at 165ºC for 30 minutes
Management and Economics wood
Lila Asadi khoramabadi; Abolghasem Khazaeian; Mohammad reza Masteri Farahani; Alireza Shakeri
Abstract
Heat treatment is one of the processes used to modify the properties of wood. The investigation of thermal treatment of wood has led to the improvement of heat treatment with vegetable oils. Heat treatment improves the dimensional stability and biological durability, but reduces the mechanical properties ...
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Heat treatment is one of the processes used to modify the properties of wood. The investigation of thermal treatment of wood has led to the improvement of heat treatment with vegetable oils. Heat treatment improves the dimensional stability and biological durability, but reduces the mechanical properties of wood. In this research, to improve the mechanical properties with other properties of wood, soybean oil modified with maleic anhydride was used for thermal treatment. Wood speciments were subjected to heat treatment soybean oil modified with maleic anhydride at two temperature (180 and 200° C ) and three time (2, 4 and 6 hours). Untreated beech was used as comparison for each treatment conditions. In this study, the effects of heat treatment on physical properties )water absorption and volumetric changes) and mechanical properties such as Bending strength) ISO 3133-1975(, Compression strength Parallel to grain) ISO 3787-1976 (and Impact bending) DIN 52189( were examined. The test results of heat-treated with modified soybean oil and control samples showed that physical and mechanical properties increases with heat treatment.
Composite wood products
Ghonche Rassam; Hamid Reza Taghiyari; Bratali Keshtegar
Abstract
Wood-composites are susceptible to fire due to their nature. Some research projects were therefore carried out to investigate potentiality of bentonite nanoparticles in improving fire-retarding properties in medium-density fiberboards (MDF); the present complimentary study aimed at determining the effects ...
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Wood-composites are susceptible to fire due to their nature. Some research projects were therefore carried out to investigate potentiality of bentonite nanoparticles in improving fire-retarding properties in medium-density fiberboards (MDF); the present complimentary study aimed at determining the effects of nanobentonite on physical and mechanical properties of MDF. Ten percent of urea-formaldehyde resin was used as adhesive in the matrix. Nano bentonite was added at 5 levels (%0 ,% 5 ,% 10 , %15 and %20) g/kg based on the dry weight of fibers. Bentonite nanoparticles were sprayed on the fibers after being mixed with the resin solution. Mats were hot-pressed for 4, 5, and 6 minutes at temperature of 170°C. Density was kept constant (75 g.cm-3) for all treatment. Results revealed that nano Bentonite did not improve the physical properties of water absorption, thickness swelling and mechanical properties of internal bonding (IB), modulus of elasticity (MOE), modulus of rupture (MOR). As to the other treatments, nano Bentonite consumption level of % 5 showed the lowest negative effect on the physical properties (water absorption, thickness swelling ) and treatment of 5% and %10 also less negative effect on the Mechanical properties (Modulus of rupture, Internal Bonding ). Treatment 20% is not recommended because it weakens the properties; moreover, the surface of fiberboards is not suitable. It was concluded that due to the fire-retarding improving effects, %5 of nano Bentonite is recommended as the optimum level for the industry.
Composite wood products
Amineh Behzadi Shahrebabak; Mehrab Madhoushi; Mohammad reza MastriFarahani
Abstract
In this study, the effect of nanoclay and coupling agent on decay resistance and physical properties (including water absorption and thickness swelling) of nanoclay- Polyethylene- MDF sanding- powder composite were investigated. For this aim, MDF sanding dust and polyethylene were used as lignocellulose ...
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In this study, the effect of nanoclay and coupling agent on decay resistance and physical properties (including water absorption and thickness swelling) of nanoclay- Polyethylene- MDF sanding- powder composite were investigated. For this aim, MDF sanding dust and polyethylene were used as lignocellulose and thermoplastic material respectively. Also, Maleic anhydride grafted polyethylene (MAPE) was used in different weight percentages; 3% and 6% as a compatibilizer and nanoclay .Cloisite®15A was used in different weight percentages 2%, 4% and 6%.At first, raw materials were producted to fabricate granules by using twin-screw extruder. Then 36 panels (12 treatments by 3 repetitions) were made by hot pressing with 1 g/cm3 nominal density at dimensions by 30 cm × 28 cm × 1 cm. Then, water absorption and thickness swelling and decay resistant (loss weight) were investigated. Specimens were exposed to Trametes versicolor for 3 months, according to ASTM-D1413 standard. The results shown, water absorption and thickness swelling reduce with increasing MAPE significantly. While, at the time when nanoclay was added 2% (phr), water absorption and thickness swelling reduced significantly and then increased. Also, decay resistance was improved with increasing coupling agent and nanoclay.
Management and Economics wood
mohammad ghofrani; vajihe farshchi; majid azizi
Abstract
Nowadays, producers are successful in Of getting profit in more efforts to satisfy our customers in target markets And build customer loyalty to your brand. The aim of this study was to study and identify factors influencing loyalty Customer to the brand in the furniture industry using Group Decision ...
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Nowadays, producers are successful in Of getting profit in more efforts to satisfy our customers in target markets And build customer loyalty to your brand. The aim of this study was to study and identify factors influencing loyalty Customer to the brand in the furniture industry using Group Decision Making method., For the purpose of study and research Been done by others, the factors affecting customer loyalty divided in to 4 main categories and 20 sub-indicators. After getting customer buyer furniture opinions via questionnaire, the priority rates of obtained criteria and sub-criteria were determined by Analytical Hierarchy Process (AHP).The results show that customers Satisfaction and marketing criteria have the highest weighting values at the first level. In addition, among 20 effective sub-criteria, Influence on customer loyalty in the furniture dustry, service quality ,reasonable price ,installment sales, warranty and perceived quality have highest priorities as 0.323, 0.151,0.129, 0.074 and 0.053 weighting values, respectively.
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
Management and Economics wood
Mohammad Kazem Eraghi; Ebrahim Barrani
Abstract
Abstract:Due to the nature of wood and paper companies and the risks and incidents in which there is, the importance of safety and safety culture is essential for working in these industries. The aim of present study was to investigate the knowledge and attitudes of employees regarding safety culture.In ...
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Abstract:Due to the nature of wood and paper companies and the risks and incidents in which there is, the importance of safety and safety culture is essential for working in these industries. The aim of present study was to investigate the knowledge and attitudes of employees regarding safety culture.In this cross-sectional study ,236 workers were examined and the data confirmed the reliability and validity of the questionnaire were collected. The data using appropriate statistical tests were analyzed by spss software. A total of 236 persons, 64% wrere high school graduated and less than, 8% were Technicians and 18% were BA and MA. Mean years of age and experience, respectively were 19.55, 7.02, 43.65, 7.40, sd, respectively. The results showed that eight important factors has the most important role for contributing of the safety culture. After the factors rotation on each other, the variance accounted for over 45% of the variance that the three first factors ,management commitment, the level of information exchange, directing to the rules and Instructions are 11.41, 9.6 and 5.05 respectively.Eight factors influence on improving the safety function and proper development of safety function in the studied companies. Managers with appropriate training programs, work safety and safety of staff will play an important role in the culture and knowledge of safety.
Management and Economics wood
Kazem Dost Hosseini; Maryam Ghorbani kobandeh; Samira Mohammad ali bighi; Alinaghi Karimi
Abstract
This research was conducted to evaluate the effects of acetylation and the resin type on three layered populus particleboard against white-rot fungus, Trametes versicolor. Populus particles were acetylated at three levels of acetyl content (WPG of 0, 8.39% and 17.27%). In manufacturing of single and ...
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This research was conducted to evaluate the effects of acetylation and the resin type on three layered populus particleboard against white-rot fungus, Trametes versicolor. Populus particles were acetylated at three levels of acetyl content (WPG of 0, 8.39% and 17.27%). In manufacturing of single and three layered boards with acetylated particles two type of resin, urea formaldehyde and isocyanate( as adhesives) were employed.
The results indicated positive role of acetylation in reducing decay rate. Weight loss of boards made from isocyanate was less than the boards containing urea formaldehyde resin. Also, three layered boards showed higher resistance against the fungus compared with single layered boards.
Management and Economics wood
Mohammad mehdi Parhizkari; asghar tarmian; Hamid Reza Taghiyari; Alinaghi Karimi
Abstract
The longitudinal gas permeability of tension wood and normal wood of Populus nigra dried by two different drying conditions was measured. Board specimens were dried under mild conditions (50ºC, and ٪63 relative humidity) to reach ٪11.8 MC, and under severe conditions (62ºC, and ٪35 RH) to ...
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The longitudinal gas permeability of tension wood and normal wood of Populus nigra dried by two different drying conditions was measured. Board specimens were dried under mild conditions (50ºC, and ٪63 relative humidity) to reach ٪11.8 MC, and under severe conditions (62ºC, and ٪35 RH) to reach ٪7 MC. After drying, dowel specimens of 14 mm in diameter and 40 mm length were prepared. Epoxy resin was applied all around each specimen to prevent fluid passing through lateral direction. Results showed that under both moisture conditions, longitudinal gas permeability values in normal wood were greater than those in tension wood. Furthermore, the permeability of both tension and normal wood decreased by increasing of drying intensity and decreasing of final moisture content.
Management and Economics wood
Asghar Taremian; Mahdi Shahverdi; Saeid Eshaghi; Hadi Dashti
Abstract
In this study, the susceptibility of poplar (P. nigra) tension and normal wood to collapse during drying was investigated. Thus, the poplar boards with nominal dimensions of 100 × 50 × 25 mm (L×T×R) were dried using three different drying schedules. In schedule A, the boards were ...
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In this study, the susceptibility of poplar (P. nigra) tension and normal wood to collapse during drying was investigated. Thus, the poplar boards with nominal dimensions of 100 × 50 × 25 mm (L×T×R) were dried using three different drying schedules. In schedule A, the boards were dried under constant conditions (dry-bulb temperature of 600C and wet-bulb temperature of 440C); in schedules B and C, they were dried under a time-based schedule, consisting of 4 and 2 steps, respectively. The initial dry-bulb temperature in schedules A, B and C were selected as 60, 60 and 820C, respectively. After drying, the severity of collapse in the cross section of boards was determined by scanning electron microscope (SEM). The results revealed that collapse did not occur in the boards dried by schedule A. Collapse occurred slightly in the boards dried by schedule B and severe collapse and cell wall degradation developed in the boards dried by schedule C. In the latter, gelatinous layer of tension wood was separated from fiber cell walls. Tension wood was more sensitive to collapse than normal wood. Based on the results, it can be concluded that the occurrence of collapse is influenced by initial dry-bulb temperature rather than wet-bulb depression.
Management and Economics wood
Alireza Mohammadi; Taghi Tabarsa; Mohammad Tasoji
Abstract
In this paper effect of static densification of treated paulownia on relationship between strength properties and density was investigated. Specimens were steamed at 130 and 170oc and immediately were compressed to 35% and 45% of their original thickness in radial direction. Mechanical properties such ...
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In this paper effect of static densification of treated paulownia on relationship between strength properties and density was investigated. Specimens were steamed at 130 and 170oc and immediately were compressed to 35% and 45% of their original thickness in radial direction. Mechanical properties such as bending strength, brinell surface hardness and compression strength in axial and radial direction were determined for non-densified and densified wood. Indexes of density, strength, quality and strength potential were calculated to study the relationship between strength and density. The results show that the density index and strength index and also strengths significantly increased with increase in densification but strength potential indexes decreased. Steam treatment at 130oc had a slight positive effect on the strengths and strength potential indexes as effect of softening the wood but the strength potential indexes and strengths decreased due to treatment of wood at 170oc. Generally, strength potential indexes of all tested mechanical properties show that strength of densified paulownia was lower compared to what had expected for non-densified paulownia from increasing density, which in turn demonstrate the cell walls were negatively affected by compression. Axial compression strength and brinell hardness were slightly affected by densification.
Management and Economics wood
Amir Tavakkoli; Ajang Tajdini; Mehran Roohnia; Ahmad Jahan latibari
Abstract
Corrugated board is considered as a valuable community for packaging at both international and domestic markets. Therefore for the development of corrugated board industry in Iran and to understand the variation in demand for this product, it's necessary to identify the consumption ...
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Corrugated board is considered as a valuable community for packaging at both international and domestic markets. Therefore for the development of corrugated board industry in Iran and to understand the variation in demand for this product, it's necessary to identify the consumption and production patterns as well as the most important and effective variables influencing it's status. Then the demand & supply for corrugated board can be forecasted. In this study, the dynamic econometric model has been used to demonstrate simultaneous relationship between supply and demand. Coefficients of the model were estimated using 3sls method with the time series data from 1981 to 2007. The results indicated that in the demand function, intercept, price, GNP in previous period, population, CPI, industrial added value(Iav), production index of large-scale industries(PILSI) and the war dummy variables are significant at 0.05 level. In the supply function, intercept, production quantity in previous period, inflation rate, corrugated board price-raw material price ratio in previous period, import quantity in previous period, cost price all in previous period and subsidy dummy variables are significant at 0.05 level. Results indicate that the mentioned variables influence consumption and production, simultaneously. The results of projection also demonstrate that corrugated board production & consumption will increase into 2012.
Management and Economics wood
Sohrab Rahimi; Mohammad mehdi Faezipoor; Saeid Eshaghi; Asghar Taremian
Abstract
Poplar lumbers with nominal thickness of 5 cm from Taleghan region, located in west of Karaj were dried under three different schedules including T8-F4 (recommended schedule by F.P.L for poplar), T8-F5 and T9-F4. The purpose of this research was to study the effects of the kiln’s rows (upper, middle, ...
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Poplar lumbers with nominal thickness of 5 cm from Taleghan region, located in west of Karaj were dried under three different schedules including T8-F4 (recommended schedule by F.P.L for poplar), T8-F5 and T9-F4. The purpose of this research was to study the effects of the kiln’s rows (upper, middle, lower) on the quality of the dried boards. Dry bulb temperatures for the schedules were adjusted at 54, 54 and 60 °C, while the final temperatures were adjusted at 82, 82 and 71 °C, respectively. The severity of warping, internal checking and surface checking in kiln dried lumbers were measured and analyzed. The results indicated that the boards in upper, middle and lower rows of the kiln, in all three schedules, did not have any significant difference in 95% confidence interval. Also, the final moisture content of the boards in all three rows and all three schedules were in acceptable quality.
Management and Economics wood
Yadolah Hossein poor; Vahid Tazkrrezaei
Abstract
In this research , beech (fagus orientalis Lipsky ) lumbers at 5 cm thickness wereran domically selected and commercially cut down from sari region(Neka choobcompany) ,with three schedule namely T5-C3, T5-C4, T6-C4 were adapted fordrying the lumbers down to the final moisture content of 8% to evaluation ...
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In this research , beech (fagus orientalis Lipsky ) lumbers at 5 cm thickness wereran domically selected and commercially cut down from sari region(Neka choobcompany) ,with three schedule namely T5-C3, T5-C4, T6-C4 were adapted fordrying the lumbers down to the final moisture content of 8% to evaluation theeffect of kiln schedule on warp and surface checking . primary dry bulbtemperature each three schedules was adjusted at 49 °C and the final dry bulbtemperatures was adjusted at 71, 71and 82°C respectively. Basic Specific gravityand dry specific gravity were measured 0.52 and 0.61 respectively. Longitudinal,radial, tangential and volumetric shrinkage were measured 0.46 %, 5.8%,10.2%, 16.46% respectively. Quantity of defect s including crook, bow, twistand three longest surface checks of the lumber were measured before and afterthe drying process in each stage. In order to analysis the lumber defects forestimating the best schedule, quality control graph were used. In the end, resultsof investigation indicated that drying of beech lumber by using of the threeschedules was desired. However the third schedule (T6-C4) had better dryingcharacteristics than the other schedules.
Management and Economics wood
Mehdi Modirzarea; Sayed khalil Hosseini hashemi; Amir Nourbakhsh; Vahid Safdari
Abstract
In this study the effect of white and brown-rot fungi on durability and hardness characteristics of Bagasse/Polypropylene composite was evaluated. The test specimens were prepared using Bagasse fibers (38%), Polypropylene (60%), and maleic anhydride (2%) according to respective standard and by hot press ...
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In this study the effect of white and brown-rot fungi on durability and hardness characteristics of Bagasse/Polypropylene composite was evaluated. The test specimens were prepared using Bagasse fibers (38%), Polypropylene (60%), and maleic anhydride (2%) according to respective standard and by hot press method. Then specimens were exposed to white (Coriolus versicolor) and brown-rot (Coniophora puteana) fungi according to BS 838:1961 standard and Kollescale method at 8, 12 and 16 weeks. After that, superficial damage, weight loss, and hardness strength of samples were determined. The results showed that superficial damage of brown-rot fungus was lower than white-rot fungus. The weight loss of white-rotted samples were significantly (P<0.05) higher than brown-rotted one, but the hardness of white-rotted samples was a little higher than brown-rotted one. Totally by increasing of time the severity of decay increased.
