Research Paper
Jafar Ebrahimpour Kasmani; Amir mohssen Nazeri; Ahmad Samariha
Abstract
Abstract: Fiber external fibrillation is one of the refining effects in conventional refining which is accompanied with a variety with other effects such as internal fibrillation. The objective of the present study was to investigate the effect of fiber external fibrillation on paper properties. Softwood ...
Read More
Abstract: Fiber external fibrillation is one of the refining effects in conventional refining which is accompanied with a variety with other effects such as internal fibrillation. The objective of the present study was to investigate the effect of fiber external fibrillation on paper properties. Softwood kraft pulp and poplar wood CMP pulp produced at Mazandaran Wood and Paper Industries was used. An ultra-fine friction grinder was used to generate the external fibrillation. The results showed that, increasing the fiber external fibrillation increased the density of paper sheets and lower refiner gaps decreased the light scattering coefficient. Increased fiber external fibrillation improved the tensile strength of the paper sheets by about 20% and internal bonding was increased from 33% to 46% compared with unrefined fibers.
Research Paper
Mosayeb Dalvand; Ghanbar Ebrahimi; Mehdi Tajvidi; Mohammad Layeghi
Abstract
The bending moment resistance under diagonal tensile load of doweled joint in plywood members was investigated. Joint members were cut from 11-ply hardwood plywood (Beech, Hornbeam and Alder) at the nominal thickness of19 mm. Dowels were made of Beech and Hornbeam woods. Dowel diameters (6, 8 and10 mm) ...
Read More
The bending moment resistance under diagonal tensile load of doweled joint in plywood members was investigated. Joint members were cut from 11-ply hardwood plywood (Beech, Hornbeam and Alder) at the nominal thickness of19 mm. Dowels were made of Beech and Hornbeam woods. Dowel diameters (6, 8 and10 mm) and depths of penetration (9, 13 and17 mm) in the joint members were selected as variables. The effect of dowel variables on the bending moment of the corner joints was evaluated. Results showed that the dowel diameter, penetration depth and species exerted a significant effect on the bending moment resistance under diagonal tensile load. Bending moment resistance under diagonal tensile load was increased as the diameter of the dowel increased from 6 to8 mmand as the penetration depth of dowel increase from 9 to13 mm. However, increasing the diameter from 8 to10 mmor the penetration depth from 13 to17 mmhad no significant effect on bending moment resistance under diagonal tensile load. Results also indicated that bending moment resistance of joints made with beech wood dowels provided higher resistance than hornbeam dowels.
Research Paper
Iman Rashidi joibari; Mohammad Azad falah; Yahya Hamzeh; Hossein Resalatii; Saeid Mahdavi
Abstract
Mechanical and chemi-mechanical pulps such as CMP, due to the weaker strength properties, have found limited application in the production of high quality papers as compared with chemical pulps. Therefore, appropriate modification of such fibers could be used to overcome such deficiencies. This study ...
Read More
Mechanical and chemi-mechanical pulps such as CMP, due to the weaker strength properties, have found limited application in the production of high quality papers as compared with chemical pulps. Therefore, appropriate modification of such fibers could be used to overcome such deficiencies. This study investigated the effect of cationic pretreatment of the CMP fibers to improve the potential of the fibers in paper production. First, fibers were treated by 20% sodium hydroxide, and then the fiber surface was cationized by grafting with one of the dosages of 5, 10 and 15% EPTMAC, based on fiber oven dry weights. The cationized fibers were mixed with 100, 20 and 40 % non-cationized fibers and the mixture was used to make hand sheets. The tensile and burst indices of the hand sheets were measured. The highest tensile and burst indices were measured on hand sheets produced containing either 20 or 40% fibers grafted with 10% cationic agent.
Research Paper
Hossein Rangavar; Abdolrasool Oromiehie; Arsalan Safarpour; Taherh Gholipour
Abstract
The present study investigated the application of recycled polyvinyl chloride (PVC) in wood-plastic composite. Wood flour having the particle size of 150 mesh, was produced from a mixture of different hardwoods and used as filler at three levels of 30, 40, and 50% based on the dry-weight of the composite. ...
Read More
The present study investigated the application of recycled polyvinyl chloride (PVC) in wood-plastic composite. Wood flour having the particle size of 150 mesh, was produced from a mixture of different hardwoods and used as filler at three levels of 30, 40, and 50% based on the dry-weight of the composite. Three types of PVC were used as the matrix (100% virgin PVC, 100% recycled PVC, and a mixture of the equal weight of virgin and recycled PVC). Maleic anhydride grafted polypropylene (MAPP) was used as the coupling agent at a fixed dosage of 5% based on the PVC weight. The composite panels were produced using injection molding and the physical and mechanical properties of the final boards were evaluated according to ASTM standard test methods. Results showed that the utilizing the mixture of virgin and recycled PVC increased the bending strength and modulus of elasticity. Water absorption was also increased. However, impact resistance and elongation at yield point were decreased. At higher wood flour content up to 40%, flexural strength was increase indicating that the resin properly encapsulated the wood flour particles and at higher wood flour dosage, elongation and Izod impact resistance was reduced.
Research Paper
ّFahimeh Shabanalizadeh; Mohammad reza Dehghani firoz abadi; Abolfazl Karegarfard; Mehrab Madhoshi
Abstract
Utilization of kenaf core and stalk for the production of medium density fiberboard was investigated. Control boards were produced using poplar wood fibers and compared with kenaf boards. Urea formaldehyde resin was used. Medium density fiberboards were made at two densities of 0.55 and 0.75 g/cm3. ...
Read More
Utilization of kenaf core and stalk for the production of medium density fiberboard was investigated. Control boards were produced using poplar wood fibers and compared with kenaf boards. Urea formaldehyde resin was used. Medium density fiberboards were made at two densities of 0.55 and 0.75 g/cm3. Six combinations of variable were tested and for each combination of variables, 3 replications and the total of 18 laboratory MDF boards were produced. The kenaf core and stalk fiber dimensions and the mechanical and physical properties of the MDF boards were measured. Factorial experimental design was used for statistical analysis of generated data. Results showed that average length of kenaf core and stalk fiber are 3.607 and 0.78 mm, and their respective diameters are 41.48 and 36.76 μm. The results of modulus of rupture, modulus of elasticity, internal bonding and thickness swelling after 2 and 24 hours immersion in water showed that kenaf core fiberboard with the density of 0.75 g/cm3 are above the required values for these boards which indicate that these properties are comparable with MDF from wood. It can be expressed that kenaf core fibers can substitute the poplar wood fiber for MDF production. The modulus of rupture, modulus of elasticity and internal bonding of MDF boards produced using kenaf core was improved as the density of the boards increased. The thickness swelling after 2 and 24 hours immersion in water was comparable to poplar fiberboard. Kenaf stalk fiberboard showed lower mechanical and physical properties due to the presence of bark fibers.
Research Paper
vahid reza Safdari; Milad Nasiri; Hamid Jodi; seid khalil Hosseini hashemi
Abstract
Wood chemical components are among the most important and effective factors in the fixation of water-borne preservatives in the wood. This research investigated the effect of wood extractive on fixation and leaching of “arsenic copper chromate“(ACC) preservative in beech (Fagus orientalis) ...
Read More
Wood chemical components are among the most important and effective factors in the fixation of water-borne preservatives in the wood. This research investigated the effect of wood extractive on fixation and leaching of “arsenic copper chromate“(ACC) preservative in beech (Fagus orientalis) wood blocks. Three groups of wood blocks (control, as wood with extractive, wood pre-extracted with hot water and wood pre-extracted with ethanol acetone) were impregnated with 2% ACC and then were placed in an incubator for 0, 192, 384, 576, and 768 hours at 25 ºC and 75% humidity. After removal from the incubator, the blocks were extracted and the preservative solution of each block was analyzed. The Cr(VI) of the extracted preservative, as the indication of the fixed amount in wood was analyzed using UV spectroscopy and the Cu and Cr contents was measured by atomic absorption. The results showed that the effect of hot water-soluble extractive on fixation and leaching of ACC was significant (P<0.01). The lowest content of unfixed Cu and Cr components was detected from control samples which indicate that the extractive imparts positive effect on fixation. The percentage of unfixed ACC in control samples was significantly lower than in pre-extracted samples.
font�X e9���h��bidi-font-size:11.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:"B Lotus"; color:black;mso-bidi-language:FA'>ACC دو درصد (2%) اشباع و در زمانهای صفر، 192، 384، 576 و 768 ساعت در داخل انکوباتور تحت رطوبت 75% و دمای 25 درجه سانتیگراد قرار گرفتند تا در چوب تثبیت شوند. سپس از مواد حفاظتی هر یک از بلوکهای چوبی عصارهگیری و مقدار کروم شش ظرفیتی موجود در عصاره که مبین تثبیت ماده حفاظتی است از طریق دستگاه اسپکتروسکوپی (UV-V) و مقدار عناصر مس و کروم کلی موجود در عصاره که نشانگر مقدار مواد تثبیت نشده در چوب میباشد بهوسیله دستگاه جذب اتمی اندازهگیری شدند. نتایج نشان داد که ماده استخراجی محلول در آب در تثبیت ماده حفاظتی ACCاثرهای مطلوب و معنیداری داشته است. بهطوریکه کمترین مقدار مس (Cu) و کروم کلی (Cr) در نمکهای حفاظتی عصارهگیری شده از نمونه چوبهای شاهد (واجد ماده استخراجی) مشاهده شد که مبین تثبیت بهتر مواد حفاظتی در این دسته از بلوکهای چوبی است (P<0.01). همچنین نتایج حاصل از آبشویی نمونه بلوکهای چوبی نشان داد که نمونههای شاهد (دارای ماده استخراجی) پس از آبشویی در مقایسه با نمونههای عاری از مواد استخراجی مقدار نمک کمتری را از دست داده است و تفاوت آنها از این لحاظ معنیدار بوده است (P<0.01).
Research Paper
Mohammad amin Andalibian; Saeid Mahdavi; Hossein Kermanian; Omid Ramezani
Abstract
The possibility to improve the test liner board properties using mechanical treatments (refining) was studied. Old Corrugated Container (OCC) fibers used in a recycled paper manufacturing company were quantitatively and qualitatively analyzed and hardwood and softwood fibers content were estimated as ...
Read More
The possibility to improve the test liner board properties using mechanical treatments (refining) was studied. Old Corrugated Container (OCC) fibers used in a recycled paper manufacturing company were quantitatively and qualitatively analyzed and hardwood and softwood fibers content were estimated as 22.6% and 60%, respectively. The mechanical treatment of pulp fiber was performed in a Valley Beater until the target freeness of 400 ml CSF. Then hand sheets with the basis weight of 127 g/m2 were made and the apparent density, Gurley air resistance, burst strength, folding endurance, Elmendorf tear strength, tensile strength and RCT were measured according to TAPPI standards. The results showed that all the properties of the refined sample increased compared to the control sample. Comparing the strength properties of the paper produced from refined pulp with the relevant values in Iranian national standards indicated the 33%, 50%, 117% increase in burst index, tensile index, and tear index, respectively. The refined pulp RCT strength increased by 28% compared to that of control sample. As the results indicated, test liner boards with suitable strength can be manufactured locally and even exported.
Research Paper
Mohammad reza Ghaznavi; Mehran Rohnia; Abdolsaber Yaghmaeipour
Abstract
The possibility of estimating some acoustical properties of particleboard panels such as "Acoustical coefficient" and "Acoustical Converting efficiency" using vibrational non-destructive techniques was investigated. Particleboard plates with the dimensions of 50×50, 100×50 and 150×50 ...
Read More
The possibility of estimating some acoustical properties of particleboard panels such as "Acoustical coefficient" and "Acoustical Converting efficiency" using vibrational non-destructive techniques was investigated. Particleboard plates with the dimensions of 50×50, 100×50 and 150×50 were used. For each plate, three replicated samples were prepared and after conditioning and the measurement of weight and dimensions, the flexural vibration test was performed on plate free-free test. In order to be ensured of the accuracy of the test, panels were converted to beams with the dimensions of 500×50×16 mm and then the same test was repeated on these samples. The results obtained from flexural vibration test of plates and beams were compared. The results indicated that it is possible to evaluate the Acoustic Coefficient and Acoustical Converting Efficiency factors with adequate accuracy using the testing method used in this study.
Research Paper
Abolfazl Karegarfard
Abstract
The objective of this investigation was the utilization of corn stalk in Medium Density Fiberboard (MDF) production. Therefore 27 laboratory MDF boards were produced using three press temperatures of 165, 175 and 185 °C and three press duration of 3, 3.5 and 4 minutes. The mechanical and physical ...
Read More
The objective of this investigation was the utilization of corn stalk in Medium Density Fiberboard (MDF) production. Therefore 27 laboratory MDF boards were produced using three press temperatures of 165, 175 and 185 °C and three press duration of 3, 3.5 and 4 minutes. The mechanical and physical properties of the boards were measured and the results were statistically analyzed. The results indicated that press temperatures and press duration did not impose significant effect on MOR, but with increasing the press temperature and press duration, the MOE of the boards improved and the highest MOE was observed applying 185 °C press temperatures and 4 minutes press duration. The internal bonding (IB) of boards increased with increasing press duration, and the highest IB was related to boards produced with 3.5 and 4 minutes press duration. The press duration significantly influenced the thickness swelling after 2 and 24 hours immersion in water, and the lowest values were observed in boards produced applying 3.5 minutes press duration, as expected from the results of highest IB at same condition. Generally it can be expressed that corn stalk shows the potential as raw material to produce standard Medium Density Fiberboard.
Research Paper
Ahmad Jahan - Latibari; Fardad Golbabaei; Abas Tamjidi; Babak Sobhani; Komail Raofkia
Abstract
Based on the need and the importance of urban wood residues to fulfill part of the wood raw material for particleboard production, and to increase its value as raw material, the potential of such material including wood residues from pine and sycamore trees as well as grape fruit tree pruning for the ...
Read More
Based on the need and the importance of urban wood residues to fulfill part of the wood raw material for particleboard production, and to increase its value as raw material, the potential of such material including wood residues from pine and sycamore trees as well as grape fruit tree pruning for the production of particleboard was investigated. The results are compared with similar particleboard produced using particles from mixed hardwoods generated at the industrial scale mill. Laboratory boards at the density of 650 kg/m3 were made changing the resin dosage at three levels of 10, 11 and 12% based on the oven dry weight of the particles and the strength and thickness swelling of the boards were measured as defined in relevant EN standards. Due to the lower bulk density of particles from pine wood, boards produced using the particles generated the highest MOR and MOE, and the lowest MOR and MOE were measured on boards produced using particles from mixed hardwoods. However, the IB of the boards on mixed hardwoods and application of 12% resin was superior (1.18 MPa.) and the lowest 1B (0.36 MPa.) was measured on the boards produced using the mixture of 50% pine and 50% sycamore particles. The thickness swelling of the sycamore boards were inferior and the lowest thickness swelling was measured on the pine particleboards.
Research Paper
Hamed Matini behzad; Asghar Taremian
Abstract
Poplar wood flour was spray treated with two preservative materials, (Thiabendazole or Carbamate derivatives (IPBC) with concentration of 0.9%) and then the wood/polyethylene composite samples with the composition of 60% wood, 38% polyethylene and 2% coupling agent were manufactured. The treated composite ...
Read More
Poplar wood flour was spray treated with two preservative materials, (Thiabendazole or Carbamate derivatives (IPBC) with concentration of 0.9%) and then the wood/polyethylene composite samples with the composition of 60% wood, 38% polyethylene and 2% coupling agent were manufactured. The treated composite and control samples were exposed to weathering for 5 months using ASTM D1435 standard test method and the structural changes of the samples were analyzed using SEM microscopy. The roughness of WPCs was measured by roughness measuring device (Miyutoyo SJ 201P) before and after weathering. The SEM images showed that the highest surface changes due to weathering occurred in untreated samples. Both preservatives improved the weathering resistance of treated WPC. The differences in the roughness values root mean square roughness (Rq), mean peak-to-valley height (Rz) and average roughness (Ra) before and after weathering were measured as 7.93, 38 and 4.88µm for control samples, 1.65, 21.7 and 42.2 µm for Thiabendazole-treated and 1.2, 1.5 and 0.79 µm for IPBC-treated samples, respectively. Both preservative materials significantly improved the weathering resistance of WPCs.
Research Paper
Amir Mollahassani; Azhang Tajdini; Mehran Roohnia; Amir Tavakkoli
Abstract
The demand for the import of lumber as one of the most important imported sawnwood inIranduring the period of 1984 to 2009 is empirically analyzed using anOrdinary Least Squaremodel (OLS). Prior to estimation, Augmented Dickey Fuller (ADF) and Philips-Perron tests were applied to investigate the stationary ...
Read More
The demand for the import of lumber as one of the most important imported sawnwood inIranduring the period of 1984 to 2009 is empirically analyzed using anOrdinary Least Squaremodel (OLS). Prior to estimation, Augmented Dickey Fuller (ADF) and Philips-Perron tests were applied to investigate the stationary character of the data. Also, to test the presence of Serial Autocorrelation in the error of the regression model Breusch-Godfrey test is used. The presence of a long-run relationship between demand for lumber import and the factors effective on it was measured by Engle –Granger and Johansen- Julius Cointegration tests and finally the causal relation in short-run was analyzed by the causality test of Granger. The results indicated that the nominal exchange rate and domestic production quantity variables imparts adverse impact and GDP and the export petroleum income impose positive impact on demand for import of lumber. Also, the results showed that there exist a long –run equilibrium relationship between lumber imports inIranand the selected macroeconomic and market variables. We find that there is a one-side causal relation from the mentioned explanatory variables to the dependence variable.
Research Paper
Habib alah Khademi eslam; Zahra Yoosefnia; Esmaeil Ghasemi; Mohammad Talaeipoor
Abstract
The effect of nanoclay and coupling agent contents on the mechanical properties of wood flour/ polypropylene/ nanoclay composites was investigated. Wood flour content was constant at 40%, maleic anhydride at two levels of 2 and 4% and nanoclay (Cloisite 30B) at four levels of 0, 1, 3 and 5% were used. ...
Read More
The effect of nanoclay and coupling agent contents on the mechanical properties of wood flour/ polypropylene/ nanoclay composites was investigated. Wood flour content was constant at 40%, maleic anhydride at two levels of 2 and 4% and nanoclay (Cloisite 30B) at four levels of 0, 1, 3 and 5% were used. The materials were mixed in an internal mixer at 180 o C, 60 rpm for 12 minutes, and then the specimens were fabricated by injection molding method. The mechanical properties such as tensile and flexural strength, flexural modulus and impact strength were measured. The nanoclay dispersion was examined by X-ray diffraction. The results indicated that the tensile and flexural strength, and the flexural modulus increased with increasing the nanoclay, but impact strength decreased. The tensile and flexural strength, flexural modulus increased as the compatibilizer content increased from 2 to 4%, but impact strength was decreased. The structural examination of the wood polymer nanocomposite with X-ray showed that nanoclay was distributed as intercalation structure in polymer matrix, and the d-spacing of layers were increased with increasing of nanoclay particles content.
Research Paper
Habib alah Khademi eslam; Razieh Baghbani; Esmaeil Ghasemi; Behzad Bazyar
Abstract
Flexural strength, modulus and tensile strength of composites made from treated baggase flour/recycled polyethylene was investigated. Baggase flour (40 mesh particles) was treated with 10% hydroxide sodium for 45 minutes. Then, the composites were manufactured using injection molding method using both ...
Read More
Flexural strength, modulus and tensile strength of composites made from treated baggase flour/recycled polyethylene was investigated. Baggase flour (40 mesh particles) was treated with 10% hydroxide sodium for 45 minutes. Then, the composites were manufactured using injection molding method using both treated and virgin baggase flour as filler (46 and 26%), and recycled and virgin polyethylene as matrix. Flexural strength of the composites made from treated fiber was superior to the relevant untreated fibers. Chemical modification of bagasse fiber improved the tensile strength. Increasing the fiber ratio from 26 to 46%, increased the flexural strength, modulus and tensile strength of the composite. Flexural and tensile properties of the composites produced using recycled HDPE were identical to those based on virgin HDPE.
Research Paper
Shima Ramezani; Mohammad Talaeipoor; Misam Aliabadi; Asghar Tabeai; Behzad Bazyar
Abstract
Samples were prepared from the native poplar species (Populus alba) grown in Mehnan, a region in Bojnourd at the ages 5 and 25 and the anatomical, biometrical and chemical characteristics of the samples sections in three directions (cross section, radial and tangential) of the tree were measured. ...
Read More
Samples were prepared from the native poplar species (Populus alba) grown in Mehnan, a region in Bojnourd at the ages 5 and 25 and the anatomical, biometrical and chemical characteristics of the samples sections in three directions (cross section, radial and tangential) of the tree were measured. Dioxan and Klason lignin were measured. Structural similarities in vascular cavities or impacted vessels in the form of binary, tripple or tetraploidy groups in juvenile and mature wood was observed primarily in radial direction. Fiber length and cell wall thickness variation in the juvenile and mature wood was significantly different and as the age of the tree increases, such difference is more significant. This point need to be considered by cellulose industries. As the age of the tree increase and the wood matures, significant change in vessel size in samples from 5 or 25 years old trees was not detected. The result showed that the older wood contains lower content of extractive and lignin and higher content of cellulose
