Research Paper
Composite wood products
Abolfazl Kargarfard
Abstract
The of utilization corn stalk residues in combination with poplar wood for particleboard production is investigated. Four combinations of corn stalk and P.nigra particles (100% corn stalk; 75% corn stalk, 25% poplar wood; 50% corn stalk, 50% poplar wood and 25% corn stalk, 75% poplar wood) is used. Two ...
Read More
The of utilization corn stalk residues in combination with poplar wood for particleboard production is investigated. Four combinations of corn stalk and P.nigra particles (100% corn stalk; 75% corn stalk, 25% poplar wood; 50% corn stalk, 50% poplar wood and 25% corn stalk, 75% poplar wood) is used. Two resin contents of 10 and 12% and two press temperatures of 170 and 180C is employed.
The results showed that increasing press temperature from 170 to 180C, decreased both MOR and MOE of boards and increasing resin content from 10 to 12%, improved MOR. When the ratio of poplar wood to corn stalk increases, both MOR and MOE of the boards increases and the highest values were reached at 50 and 75% poplar wood. Higher press temperature and lower ratio of corn stalk improved internal bond (IB). Higher press temperature, resin content and lower ratio of corn stalk, decreased thickness swelling. Based on the results, with application of either 25 to 50% corn stalk and press temperature of 170C, standard particleboard can be produced.
Research Paper
Abas Fakhryan; Hossein Hosseinkhani; Fardad Golbabaei; Mohammad mehdi Brazandeh
Abstract
In this Investigation chemical, physical, morphology, pulp and paper making characteristics of Populus costanzo were studied. The average dry and critical specific gravity was found to be 0.39and 0.36 and the fiber morphology including fiber length , diameter ,lumen and thickness ...
Read More
In this Investigation chemical, physical, morphology, pulp and paper making characteristics of Populus costanzo were studied. The average dry and critical specific gravity was found to be 0.39and 0.36 and the fiber morphology including fiber length , diameter ,lumen and thickness of cell wall 1.14 mm,28.84 µm, 28 µm ,and 2.92 µm was determined respectively. The average chemical composition including cellulose 50.74%, lignin 19.18%, Ext. 1.22% and Ash 1.65% were measured. In order to cook and pulping, Kraft process was used. The maximum yield and kappa number of Populus costanzo at 1 hour cooking time, 150°c cooking temperature and 12% effective alkali condition obtained at 61.91% and 54.83 respectively and the minimum yield and kappa number at 3 hour cooking time, 170°c cooking temperature and 16% effective alkali condition obtained at 45.63% and 13.42 respectively.
Research Paper
Physics and Mechanical Wood
Fardad Golbabaei; Hossein Hosseinkhani; Amir Nourbakhsh; Abolfazl Kargarfard; Abas Fakhryan
Abstract
Most industrial production processes need cooling water to operate efficiently and safely. Refineries، steel mills، petrochemical manufacturing plants، electric utilities and paper mills all rely heavily on equipment or processes that require efficient temperature control. Cooling water system control ...
Read More
Most industrial production processes need cooling water to operate efficiently and safely. Refineries، steel mills، petrochemical manufacturing plants، electric utilities and paper mills all rely heavily on equipment or processes that require efficient temperature control. Cooling water system control these temperatures by transferring heat from hot process fluids into cooling water. As this happens، the cooling water itself gets hot before it can be used again it must either be cooled or replaced by a fresh supply of cold water. The aim of this study was utilizing domestic wood in cooling towers structure. For this purpose، five wood spices included: Hornbeam، Oak، Alder،Populus and Tehran pine (Eldarica pine) and also five different regions with different climate، included: electric plant Montazer ghaem from Karaj near of Tehran، electric plant Loshan from north of Iran، electric plant Dorcheh Esfahan from center of Iran and petrochemical manufacturing plants Bandar emam from south of Iran، have been chosen. Sampling have been done and treated with CCA. All samples were put in the cooling towers and were tested during the study period. (Mechanical tests such as specific gravity، static bending، compression parallel to grain and hardness). Based on this study، the mechanical properties of these spices during last four years were done. At the fifth year of study، virtual damages have not seen where as significant difference have been achieved in aspect of mechanical properties. Among of theses wood spices، Populous and Pinus eldarica had minimum mechanical degrade and it should be noted that Pinus eldarica spices had better quality than populous spices.
Research Paper
Physics and anatomy
Farshid Basiji; Vahid reza Safdari; Ahmad Jahan latibari; Amir Nourbakhsh
Abstract
The objective of adding reinforcing fillers, such as natural fibers to plastics is to increase the strength compared with neat plastic and wood. In this research the effect of wood pulp fiber length (short, medium and long), aspect ratio and fiber content (27%, 37%, 47% and 0% (non-reinforced PP)) with ...
Read More
The objective of adding reinforcing fillers, such as natural fibers to plastics is to increase the strength compared with neat plastic and wood. In this research the effect of wood pulp fiber length (short, medium and long), aspect ratio and fiber content (27%, 37%, 47% and 0% (non-reinforced PP)) with 3% maleic anhydride grafted polypropylene on wood plastic composites (WPCs) has been studied. Results showed that increased fiber length or aspect ratio and fiber content increases mechanical properties (tensile strength, tensile modulus and MOE). Impact strength had an inverse correlation with fiber content and fiber length, but fiber content was a much more important factor than fiber length for impact strength. The impact strength of composite of softwood pulps was much higher than wood floor composite plastic. The significant interaction between fiber length and fiber content, and the lack of a specific trend in the treatments made assessment of the effect of fiber properties on MOR difficult.
Research Paper
Composite wood products
Farhad Ghotbaldin; Habib alah Khademieslam; Amir Nourbakhsh; Mohammad Talaeipoor
Abstract
An experiment was conducted to study polymerization conditions and important production factors, the amount of resin and press temperature, on physical and mechanical properties of produced boards by urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were compared. Purify UF resin (control treatment) ...
Read More
An experiment was conducted to study polymerization conditions and important production factors, the amount of resin and press temperature, on physical and mechanical properties of produced boards by urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were compared. Purify UF resin (control treatment) and its mixture with MUF at 25, 50 and 75% proportions in 170 and 180˚C temperature were used to make homogen particle boards. The proportion of resin to particles was 10 percent by dry weight. Other production factors were assumed as fix factors. Eight experimental groups (treatment) with three replications per each were studied. Produced particles were derived from species Alnus subcordata. Physical and mechanical properties measurement prepared samples were based on European EN standard. Examined Physical characteristics were water absorption and thickness swelling and mechanical characteristics were modulus of rupture, modulus of elasticity and so internal bond. The data were analyzed in completely randomized design with factorial arrangement (4*2). Statistical significances among treatment means were determined by multiple range test of Duncan. The results of this study showed that physical and mechanical properties of boards were improved by increasing the level of MUF resin and temperature. Eventually, with consideration all results and so quality and economical aspects of produced particleboard by MUF resin and its comparison with control group we have concluded that 50 percent of MUF resin and 180 degree centigrade of press temperature are optimal levels.
Research Paper
Management and Economics wood
Eiraj Mansoryar; Alinaghi Karimi; Ghanbar Ebrahimi; Ahmad Mirshokraei; Sohrab Rahimi
Abstract
The water repellency and dimensional stabilization of wood species are important for outdoor uses. In this study, the water absorption and water repelling of poplar wood (Populus Alba) by emulsion of paraffin, Quaternary ammonium and starch, were investigated. Paraffin in three levels of 0%, 3%, 5%, ...
Read More
The water repellency and dimensional stabilization of wood species are important for outdoor uses. In this study, the water absorption and water repelling of poplar wood (Populus Alba) by emulsion of paraffin, Quaternary ammonium and starch, were investigated. Paraffin in three levels of 0%, 3%, 5%, Quaternary ammonium in three levels of 0%, 1.5%, 2.5% and also starch in three levels of 0%, 1% and 2%(by weight) were selected as variables. A set of matched specimens were set aside as control, for making comparison. Results showed that the amount of paraffin had a positive significant effect on water absorption and water repellency that is increasing paraffin would improve these properties. Furthermore, specimens treated with paraffin had better water repellency than control samples. Based on the results, it is claimed that the treatment of 5% paraffin, 0-1.5% Quaternary ammonium and 0-1% starch will bring about water absorption and water repellency in treated specimens to a desired level, without causing any damage to other physical properties of them.
Research Paper
Pulp and paper
Iman Akbarpoor; Hossein Resalti; Ahmad reza Saraeyan
Abstract
In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, ...
Read More
In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, Enzymatic treatment was accomplished at different concentrations of 0.025, 0.05, 0.1 and 0.2% of cellulase enzyme (on the basis of oven dried waste paper), pH range of 5-5.5, different times of 10,15 and 20 minutes, consistency of 10%, temperature of 50±1!C along with washing. The results comparison of optimum chemical and enzymatic treatments showed that, deinked pulp by chemical method had higher brightness and yellowness. Also, deinked pulp by chemical method resulted the papers with higher bulk, higher caliper and higher air resistance.
Research Paper
Management and Economics wood
asghar tarmian; Amir Sepehr
Abstract
The heat transfer through three orthotropic directions and the evolution of temperature gradient in beech (Fagus orientalis) and spruce (Picea abies) during drying were investigated. Thus, due to low capacity of dryer, small flat-sawn boards with dimensions of 80 × 25 × 40 mm (L×R×T) ...
Read More
The heat transfer through three orthotropic directions and the evolution of temperature gradient in beech (Fagus orientalis) and spruce (Picea abies) during drying were investigated. Thus, due to low capacity of dryer, small flat-sawn boards with dimensions of 80 × 25 × 40 mm (L×R×T) were used. Then, the boards were dried at the dry-bulb temperature of 60 °C and relative humidity of 50 %. Four surfaces of the boards were coated by polyurethane-coated aluminum foil to confine the heat flux along one direction. Then, the boards were thermally insulated by 50 mm-thick Styrofoam. Some holes with 1mm in diameter were made on the board specific distances to measure the temperature using thermocouple. The results showed that the temperature of each wood increased as heating up progressed until it reached to the wet-bulb temperature. Then, it remained at an almost constant value as the wet bulb temperature until the wood moisture content reached the hygroscopic range. Furthermore, the pattern of the temperature profile for both wood species was almost identical. The surface temperature of the boards increased until it reached the dry-bulb temperature of 60 °C, while the core temperate remained as the wet-bulb temperature (48-52 °C) throughout the rest of drying period.
Research Paper
Physics and anatomy
Vahid Safdari
Abstract
The suitability of wood and noon-wood species for using in pulp and paper industry can be predicted by their morphological and chemical characteristics. In these research morphological and chemical properties of four spices of Ulmacea family, Ulmus glabrar, Ulmus compestris, Zelkova carpinifolia and ...
Read More
The suitability of wood and noon-wood species for using in pulp and paper industry can be predicted by their morphological and chemical characteristics. In these research morphological and chemical properties of four spices of Ulmacea family, Ulmus glabrar, Ulmus compestris, Zelkova carpinifolia and Celtis australis have been compared. From each species three cross section, 5 cm thickness has been selected. Wood slivers of tree zones: near to pith, middle part and near to bark wood have been macerated in mixture of acetic acid and hydrogen peroxide at 60°C for 48 hours. Biometric coefficients of fibers in three zone and four species have been measured and analyzed by factorial, complete randomized block design. Result showed that, Zelkova carpinifolia has least lignin, ash and extractives and highest cellulose. The fibers of, Zelkova carpinifoliahas has highest Slenderness ratio, Runkel ratio and hence in Ulmacea family is most suitable species for paper industry. Fiber length, wall thickness in near to bark zone in comparison to near to pith was higher significantly. Therefore it is predicted that the mechanical properties of pulp of this three zones are different
Research Paper
Management and Economics wood
Afshin Kshn dehghan; Habibalah Khademi eslam; Behzad Bazyar
Abstract
In this study, the influence of the fungus (Coriolus versicolor) on the durability of Horn beam (carpinus betulus) in natural state and treated with CCA (Copper/Chromium/Arsenic) was evaluated. CCA is a kind of water borne preservatives that was used to treat specimens under vacuum and pressure ...
Read More
In this study, the influence of the fungus (Coriolus versicolor) on the durability of Horn beam (carpinus betulus) in natural state and treated with CCA (Copper/Chromium/Arsenic) was evaluated. CCA is a kind of water borne preservatives that was used to treat specimens under vacuum and pressure (Bethel procedure) with amount of 3.5 & 1.5 percent on the basis of oven dry wood. Specimens were contaminated with cultured fungus for eight weeks in incubator. After this period, weight reduction, compressive strength (parallel to grain) and hardness of specimens were measured. Weight reduction of treated samples with 3.5 & 1.5 percent CCA were 1.68 and 1.73 percent respectively. Weight reduction of control samples were much higher (22.87 percent) than treated ones. There was no significant difference between the Compressive strength (parallel to grain) of treated and control samples without effect of fungus but the samples with effect of fungus have significant difference. Compressive strength (parallel to grain) of treated samples with 3.5 & 1.5 percent of CCA were 64.33 and 60.10 (Mpa) respectively but Compressive strength (parallel to grain) of control samples were much lower (38.44 Mpa) than treated samples. There was no significant difference between the hardness of treated and control samples without effect of fungus. On the other hand, the hardness of treated samples was more than control samples slightly, but this difference was not significant in 5 percent level. The hardness of treated and control samples with effect of fungus have significant difference. Hardness of treated samples with 3.5 & 1.5 percent of CCA were 5788(N) and 5799(N) respectively. However the hardness of control samples were much lower (3139N) than treated samples. Eventually CCA (Tanalith c) increased the durability of Horn beam (Carpinus betulus) from nondurable level to durable level.
Research Paper
Management and Economics wood
Meraj Sharari; Ahmad Jahan latibari; Gholamreza Rafiei; Ahmad Mirshokraei
Abstract
In the course of enhanced bioremediation, addition of nutrients such as carbon, nitrogen, phosphorous, etc, substrates, electron acceptors as well as vitamins (Thiamin, etc) and veratryl alcohol, increased metabolic activities, will influence the production of enzymes and enhances the deterioration of ...
Read More
In the course of enhanced bioremediation, addition of nutrients such as carbon, nitrogen, phosphorous, etc, substrates, electron acceptors as well as vitamins (Thiamin, etc) and veratryl alcohol, increased metabolic activities, will influence the production of enzymes and enhances the deterioration of pollutants. In this study, the effect of 1% (V/V) of nutrients containing various mineral salts, carbon (glucose and malt), nitrogen (casein peptone yeast extract) and some enzyme inducer, such as veratryl alcohol and thiamin hydrochloride on production of laccase, peroxidase and xylanase enzymes by Phanerochaete chrysosporium in bagasse preparation effluent is investigated. The results showed that MSB+MCTV is the most effective additive which causes the highest lignolitic activity of this fungus after 5 to 7 days in case of laccase and peroxidase and 3 days for xylanase, and maximizes the production of the enzymes. The production of these enzymes is measured at 78, 193 and 60 U/l respectively. However, in conditions without additives, the relevant values are 26, 54 and 16 U/l respectively. The relation between different stages of fungus growth and enzyme production and changes in lignin and carbohydrate of effluent after the period of nine days is also investigated.
Research Paper
Mohamad Tasoji; Taghi Tabrsa; Alireza Mohammadi
Abstract
For making wheat straw particleboards, different mixtures of UF and MF resins were used. The ratio of UF : MF was 0:100,75:25,50:50,25:75 and 100:0 based on weight of resin and boards densities were set to 0.7 . The physical and mechanical properties such as Thickness Swelling(TS)(after 2 and 24 hours), ...
Read More
For making wheat straw particleboards, different mixtures of UF and MF resins were used. The ratio of UF : MF was 0:100,75:25,50:50,25:75 and 100:0 based on weight of resin and boards densities were set to 0.7 . The physical and mechanical properties such as Thickness Swelling(TS)(after 2 and 24 hours), Internal Bonding(IB) , Modulus Of Elasticity(MOE) ,Modulus Of Rupture(MOR) were determined and compared to EN 312-4 standard. The highest amounts of IB ,MOR and MOE are from the boards that were made from 50:50 (UF:MF) . All of The boards MOE and MOR amounts of all treatments except treatment 100:0 (UF:MF) were in range of EN 312-4 standard but the IB amounts were not. The TS amount was improved in the boards with more MF content but it was not in EN 312-4 range. Due to the thin waxy layer that covers the outer most layer of wheat straw surface, the non polar structure of this layer brings incompatibility between polar resins and wheat straw particles and this incompatibility will result in low physical and mechanical property for wheat straw particleboards. Also due to low porosity of waxy layer, the distribution of formaldehyde polar resins on straw particles surface, not well occur and this itself is an important factor in decrease of physical and mechanical resistance in wheat straw particleboards.
Research Paper
Pulp and paper
Jalil Roshanasan; Mohammadreza Dehghani firozabadi; Mohammad Dahmardeh ghaleh no; Saeideh Sharifi
Abstract
The lignin dissolution in Kraft pulping for wheat straw was studied. Kraft pulping was carried out under the conditions: chemical charge of 18% (as NaOH, based on o.d. bagasse), sulfidity of 25% and liquor to wheat straw ratio of 10:1. Six cooking maximum temperatures of 85,100,110,120,130 and 150 ◦C, ...
Read More
The lignin dissolution in Kraft pulping for wheat straw was studied. Kraft pulping was carried out under the conditions: chemical charge of 18% (as NaOH, based on o.d. bagasse), sulfidity of 25% and liquor to wheat straw ratio of 10:1. Six cooking maximum temperatures of 85,100,110,120,130 and 150 ◦C, were selected and reaction time varied from 0 to 250 min. based on maximum temperature. The Klason lignin, acid soluble lignin, ash and extractive contents of wheat straw were 18.4%, 2.07%, 3.24% and 4.56 respectively.
During alkaline pulping of wheat straw, about 64% and 52% of lignin was removed before reaching to the temperature 100 ◦C and 85 respectively. The values pulp and carbohydrates yield were, about 64%, 58% for 85 ◦C and 61%, 57% for 100◦C.
Research Paper
Pulp and paper
Jafar Ebrahimpoor kasmani; Amir mohssen Nazeri; Ali Ashryeh
Abstract
In this investigation , effects of different humidity and heat on quality of Corrugated board , was studied , and optimum treatment indicated Variables in this Paper was : Corrugator speed (50,100,150m/min) ,wraping angle of the paper around preheaters ...
Read More
In this investigation , effects of different humidity and heat on quality of Corrugated board , was studied , and optimum treatment indicated Variables in this Paper was : Corrugator speed (50,100,150m/min) ,wraping angle of the paper around preheaters (90,180,300 degree) and moisture of paper (6.5%,7%,8.5%). Papers that treated for this purpose was included : 125gsm kraft liner ,127 gsm medium paper and 140gsm test liner paper. A flut type of 3ply Corugated board was selected for this study.Moisture of paper was measured in 3 places : Paper on roll stand before single facer , paper after singlefacer preheater and paper before incoming doublefacer in hot plate unit. Also temprature was measured in corrugator rolls ,hot Plates in double facer and final Board after Exiting of the Machine.
Results show that , warp of final board decreased in speed 50 and 100m/min ,moisture 7% and 1800 wraping angle of the paper around preheater.
That means lower speeds and higher wraping angles cause to more heat on corrugated board and decreasing in warp content resulted.It should be noted that lower humidity more than 7% and increase wraping angle more than 180 degree cause to over drying and intensive moisture decrease in final board that cause to reverse warp in final board.
Research Paper
Composite wood products
Leila Fathi; Mohammad mehdi Faezipoor; Mohsen Bahmani
Abstract
In this investigation the effect of using of UF and MUF Resins on Physical and mechanical Properties of Particleboards Produced from Rice Straw and Aspen Particles has been studied. The aim of this study was to determine of physical and mechanical properties of rice straw– particleboard. ...
Read More
In this investigation the effect of using of UF and MUF Resins on Physical and mechanical Properties of Particleboards Produced from Rice Straw and Aspen Particles has been studied. The aim of this study was to determine of physical and mechanical properties of rice straw– particleboard. Single-layer particleboard was produced. That was produced with 11% MUF and 11% UF. For using of UF and MUF 2% hardener was added to adhesives. The Press condition for MUF was: 1750C for 4 minutes and also for UF application was 1750C for 6 minutes. Another variable factor was the rice straw content in three levels (15%, 30% and 45%). Other factors such as board density (0/7gr/cm3), mat moisture (12%) were constant factors. The results indicate that increasing rice straw to wood particles cause some reduction in modulus of rupture , and internal bonding , and some increase in thickness swelling , and water absorption of manufactured boards. But comparing and grouping means by Duncan test showed that in the most case these effects were insignificant when rice straw add to wood particle up to 30%. Particleboard bonded with 11% MUF had the highest bending strength. Particleboards bonded with MUF had better bending strength, shear strength, thickness swelling and water absorption after 2, 24 hours immersion. Grouping the experimental data while using Duncan method was indicated of the fact that an optimum condition for manufacturing particleboard while using a mixture of rice straw and wood particles is to add 30% rice straw to the mixture , use 11% melamine urea formaldehyde resin and employ a pressing time of 4 minutes.
