Composite wood products
Javad Torkaman; rouzbeh asadi khansari
Abstract
Fibre-gypsum board is a composite, in which fiber used as the reinforcement in the matrix of gypsum. The purpose of this article is to investigate the effect of different amounts of waste paper fibers on the strength, resistance and the fracture behavior of fiber-gypsum board. For this purpose, amounts ...
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Fibre-gypsum board is a composite, in which fiber used as the reinforcement in the matrix of gypsum. The purpose of this article is to investigate the effect of different amounts of waste paper fibers on the strength, resistance and the fracture behavior of fiber-gypsum board. For this purpose, amounts of zero, 5, 10, 15, 20, 25 and 35 percent of waste paper fibers have been used. The results of measuring bending strength, internal bonding and moisture absorption during one month exposure to 100% relative humidity show that increasing the percentage of fibers up to 20% has increased the mechanical properties. In general, By using twenty percent fibers the bending strength increased fifty percent and the internal bonding became double and half in comparison to the control samples. The load-displacement curve shows that an increase of 5 to 15 percent of fibers does not change the fracture behavior of the fiber-gypsum board and they had brittle fracture same as control samples. While in more substitution values, the flexibility increases and the failure becomes ductile. Therefore, the best conditions in terms of strength, resistance, and flexibility have been obtained in 20% replacement of gypsum with waste paper fibers.
Jafar Ebrahimpour Kasmani; Saeed Mahdavi
Abstract
This research was carried out with aim of the effect of nano-clay (NC) content on mechanical, thermogravimetry (TG) and morphological properties of wood plastic composite (WPC) made of medium density fiberboard (MDF) and particleboard (PB) wastes and recycled polypropylene and polyethylene (HDPE). For ...
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This research was carried out with aim of the effect of nano-clay (NC) content on mechanical, thermogravimetry (TG) and morphological properties of wood plastic composite (WPC) made of medium density fiberboard (MDF) and particleboard (PB) wastes and recycled polypropylene and polyethylene (HDPE). For this purpose, wastes of MDF and PB at 50 wt.% , recycled PP and HDPE at 50 wt.%, maleic anhydride grafted with polymers at a constant level of 3 wt.% and nanoclay at three different levels 3, 6, and 9 wt.% were blended by two-wire extruder. Afterward, standard test pieces were made using an injection molding machine and their mechanical properties and TGA were investigated. Scanning electron microscope (SEM) was applied to investigate the quality of nanoclay particles dispersion in the matrice as well as how the lignocellulosic and polymers are bonded at the surface of bonding. The results showed that tensile and flexural strength and their modulus of HDPE and PB composite significantly were increased by adding NC up to 3 wt.%, but the strengths were dropped in WPC's by increasing of NC content at 6 and 9 wt.%. The notched impact strength of WPC has been totally decreased by NC addition that indicates more fracture surface on WPC's. SEM micrographs revealed that porosity and cavities in WPC's especially were decreased at 9 wt.% NC, whereas it is clear an inappropriate dispersion and aggregation of NC in WPC. The thermal stability of WPC's was slightly improved at 3 wt.% NC and the residual after combustion increased compared to the control.
Pulp and paper
Abdolrahim Mohebalian; Ahmad Jahan latibari; Ajang Tajdini; Shadman Pourmosa
Abstract
In this research, the influence of two temperatures (60 and 90°C) and three dosages of sodium hydroxide (5, 7.5 and 10%, based on the dry weight) on hornbeam wood chips alkaline pre-hydrolysis and soda pulping was studied. Soda pulping of both pre-hydrolyzed and control chips were conducted applying ...
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In this research, the influence of two temperatures (60 and 90°C) and three dosages of sodium hydroxide (5, 7.5 and 10%, based on the dry weight) on hornbeam wood chips alkaline pre-hydrolysis and soda pulping was studied. Soda pulping of both pre-hydrolyzed and control chips were conducted applying constant pulping variables. The effect of pre-hydrolysis on hemicelluloses removal and sodium hydroxide consumption and pulp characteristic including total yield, reject, pulp freeness, kappa number, and pulp strengths were measured and statically analyzed. In case the effect of variable on measured property was statistically significant, then Duncan multiple range grouping of the measured property was arranged. The result revealed that pre-hydrolysis removed almost 4.2% (based on dry wood) of hemicelluloses of the wood and pre-hydrolysis demonstrated easier soda pulping delignification, due to weakening the lignin-carbohydrate bonds and both total yield, reject and kappa number were reduced. Tensile strength index of the pulp produced using pre-hydrolyzed chips war lower and as the dosage of sodium hydroxide increases, the tensile strength index was reduced initiated from the removal of hemicelluloses which is also lower than control pulp, Tear strength index of the soda pulp from pre-hydrolyzed chips was mildly reduced which is anticipated to be the consequence of fiber weakening and fiber breaking during cooked chips defibration. The effect of pre-hydrolysis variables on tear strength was not statistically significant. Based on the result of this study, hornbeam wood can be a potential source of bio-refining based on lignocellulosic material.
Composite wood products
Abolfazl Kargarfard
Abstract
The potential of cotton stalks residues for the production of particleboard was investigated. Three resin dosage gradients (10% core:10% surface; 9%core:11% surface and 8% core:12% surface) and three press times (3, 4 and 5 minutes) were selected as the variables were produced. Then the mechanical and ...
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The potential of cotton stalks residues for the production of particleboard was investigated. Three resin dosage gradients (10% core:10% surface; 9%core:11% surface and 8% core:12% surface) and three press times (3, 4 and 5 minutes) were selected as the variables were produced. Then the mechanical and physical properties of the boards were measured and statistically analyzed. The results of modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB) measurements showed that as the resin dosage gradient increases, these properties increased and the effect of this variable on these properties was statistically significant. The highest values were reached when either 2 or 4% resin dosage gradients were applied. The effect of resin dosage gradient on thickness swelling after 2 and 24 hours immersion in water was also statistically significant and these properties were improved. The effect of press time on thickness swelling was also statistically significant and the lowest thickness swelling was observed at 5 minutes press time. The results indicated that if 2 or 4% resin dosage gradients and either 4 or 5 minutes press time is applied for the manufacturing of particleboards using cotton stalks residues, the specification of the boards meet the EN specification.
Ahmad Jahan latibari; Reza Jamail; Mehran Roohnia
Abstract
The influence of different dosages of surfactant and soap in the deinking of wastepaper is investigated. The results showed that the dosage of 0.25% soap generated highest brightness and lowest opacity. However, the dosage of 0.75% soap produced highest tensile and burst strength and 0.5% soap produced ...
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The influence of different dosages of surfactant and soap in the deinking of wastepaper is investigated. The results showed that the dosage of 0.25% soap generated highest brightness and lowest opacity. However, the dosage of 0.75% soap produced highest tensile and burst strength and 0.5% soap produced the lowest spec (dirt) index. In the case of surfactant application, the dosage of 0.75% surfactant produced highest brightness and 0.5% surfactant generated lowest opacity. Application of 0.5% surfactant showed highest tensile and burst strength and lowest dirt index. The combined effect of both chemicals showed that the combined dosage of 0.75% surfactant and 0.25% soap produces highest brightness but the dosage of 0.25% surfactant without soap produced lowest opacity. Highest tensile and burst strength was related to pulp deinked using 0.5% surfactant and 0.75% soap. The results indicated that the combination of 0.75% surfactant and 0.25% soap generated highest brightness which the important property of the writing and printing paper. The highest tensile and burst strength was measured in deinked pulp produced using 0.5% surfactant and 0.75% soap.
Seaid Masoumeh Hafezi; Ali akbar ٍEnayati; Kazem Doosthosseiny; Asghar Taremian; Ahmad Mirshokraee
Abstract
This research was conducted to investigate the effect of silane coupling agent usage to improve the bond formation of urea formaldehyde resin in wheat straw particleboard production. Three levels (0.5% and 10%; based on the dry weight of the resin) of silane coupling agent and 10% urea formaldehyde resin ...
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This research was conducted to investigate the effect of silane coupling agent usage to improve the bond formation of urea formaldehyde resin in wheat straw particleboard production. Three levels (0.5% and 10%; based on the dry weight of the resin) of silane coupling agent and 10% urea formaldehyde resin were used to produce one layer particle boards with 16mm nominal thickness. Physical and mechanical properties including MOR, MOE, IB and thickness swelling (after 2 and 24 hours immersion in water) were measured. The results of this study showed that adding silane coupling agent to the resin in wheat straw particleboard production, increased MOR, MOE and IB and dimensions stability improved. Optimum dosage for silane coupling agent to improve modulus of elasticity, internal bonding and thickness swelling was 10% and the for modulus of rupture, it was determined as 5%.
Hanieh Ghasemi; Ahmad Jahan Latibari; Abolfazl Karegarfard; Amir Lashgari
Abstract
The impact of the addition of different amounts of canola straw to the composition of the hardwood particles for the production of particleboard was investigated. Four levels (0, 15, 30 and 45%) of Canola particles were added to hardwood particles and then particles were blended with 12% urea resin (based ...
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The impact of the addition of different amounts of canola straw to the composition of the hardwood particles for the production of particleboard was investigated. Four levels (0, 15, 30 and 45%) of Canola particles were added to hardwood particles and then particles were blended with 12% urea resin (based on the oven dry weight of the particles). Boards at three densities of 550, 600 and 650 kg/m3 were produced. The flexural and internal bonding strength and water absorption and thickness swelling after 2 and 24 hours immersion in water of the boards were determined using appropriate EN standard test methods. Addition of different amounts of canola particle to the hardwood particles did not change either modulus of rupture or modulus of elasticity of the boards, but the internal bonding of the boards was reduced. As the dosage of the canola particles increased, both water absorption and thickness swelling were reduced. Increasing the density of the boards increased both strength and dimensional stability.
Abolfazl Kargarfard; Amir Nourbakhsh; Fardad Golbabaei
Abstract
The objective of this study was to investigate utilization of pomegranate pruning residues as the core layer of the three layer particleboard. The percentage of the pomegranate residues varied as 100, 65 and 35% in the core layer of the eucalypt particleboard and three resin levels of 8, ...
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The objective of this study was to investigate utilization of pomegranate pruning residues as the core layer of the three layer particleboard. The percentage of the pomegranate residues varied as 100, 65 and 35% in the core layer of the eucalypt particleboard and three resin levels of 8, 10 and 12 % (based on the weight of the wood particles) were applied in the core layer. Resin dosage in the surface layer was kept at 12 %. The strength and physical properties were measured and analyzed applying factorial model based on completely randomized design. The results revealed that if 65% pomegranate residues are used in the core layer, the modulus of rupture and modulus of elasticity were the highest and the combined effect of both variables on the properties were statistically significant. The highest value of the modulus of rupture and modulus of elasticity obtained in the case of 10% resin in the core layer and 100% pomegranate residues followed by 8% resin in the core layer and 65% pomegranate residues. The combined effect of both variables on internal bonding of the boards was statistically significant and the highest internal bonding was reached if 8% resin and 65% pomegranate residues were used in the core layer. The effect of resin dosage on thickness swelling after 24 hours immersion in water was statistically significant. The results indicated that pomegranate tree pruning could be used for the particleboard manufacturing.
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 ...
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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.
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 ...
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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.
Sasan َAbangah; Ahmad Jahan Latibari; Seyad Javad Sepideh dam; Mehran Roohnia; Mohammad ali Hossein
Abstract
The influence of reinforcing fibers (old corrugated container fibers called OCC) and addition of foaming agents (Azodicarbinamide and sodium bicarbonate) on density, strength properties and dimensional stability of OCC fiber/polypropylene composite were investigated. Conten of reinforcing fibers constant ...
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The influence of reinforcing fibers (old corrugated container fibers called OCC) and addition of foaming agents (Azodicarbinamide and sodium bicarbonate) on density, strength properties and dimensional stability of OCC fiber/polypropylene composite were investigated. Conten of reinforcing fibers constant at 20% and the content of either foaming agent varied as 3, 5 and 7%. Strength properties including MOR, MOE, maximum tensile strength and modulus as well as izod impact strength were measured. Water absorption after 2 and 24 hours soaking in distilled water at 23±2 ºC were measured. Foaming agent decomposition caused some chemical residues in composite and the diffusion and penetration of polymer into the fibers structure led to increase in the density from 839.2 kg/m3 for pure polypropylene to 919.2 - 947.9kg/m3 for the composite, MOR and MOE also increased by the addition of foaming agent and the reinforcing fiber. The effect of 5 or 7% sodium bicarbonate was statistically significant and it improved the properties of the composite. Similar results were obtained for tensile strength and the modulus. Reinforcing fibers and foaming agent caused higher impact strength of the composite. Water absorption of the composites was higher than pure polypropylene.
Pulp and paper
Ahmad Jahan latibari
Abstract
In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping ...
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In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping temperature were used. After digester yield varied between 64.65 and 71.7% and the total yield after defibration was measured as 54.45% and 62%. Unrefined pulp freeness varied between 708 and 765 ml CSF. Pulps produced applying 10-16% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected from further evaluation. These pulps were refined to about 365 ml CSF in a PFI mill and then handsheets were made for strength evaluation. The apparent density of the handsheets varied between 437-488 kg/m3, tear index between 6.51-7.11 mN.m2/g, and tensile index between 29.2 -30.8 N.m/g. Significant difference at 99% was not observed between the strength of the pulps. Then pulp produced applying 10% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected for bleaching trials. Totally Chlorine Free (TCF) bleaching sequence was used for bleaching the selected pulp. Pulps bleached applying 4% H2O2 and 3.5% NaOH, 3% sodium Silicate, 0.5% MgSO4 and 0.3% DTPA for 2 hours showed the highest brightness of 50.69% compared to 29.2% for unbleached pulp.
Pulp and paper
Mohammad ali Azad far; Rabie Behroz; Ahmad Jahan - Latibari
Abstract
The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum ...
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The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum Kappa no, yield and brightness, opacity and strength based on 60 g/m2 hand sheets were determined. The results indicated that application of oxygen delignification marginally reduced the opacity of the pulp. Tear strength increased where as tensile and burst strength decreased. Based on the comparison of the data from oxygen delignified pulp, it is concluded that oxygen can be utilized to improve the properties of soda-AQ pulp from OCC prepared for bleaching step. Carbohydrates are preserved while removing lignin. Normalized equations revealed that oxygen delignification at 3% alkali produced the best results.
Pulp and paper
Omid Hosseinzadeh; Ahmad Jahan latibari
Abstract
The influence of pulping temperature and time on strength properties of bagasse soda pulp was investigated. Two cooking temperatures)175ْC,185 ْC (and three cooking times (20,30,40 minutes) were selected .The other variables were kept constant at 18 % NaOH and l/w=8. Tensile strength, tear strength ...
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The influence of pulping temperature and time on strength properties of bagasse soda pulp was investigated. Two cooking temperatures)175ْC,185 ْC (and three cooking times (20,30,40 minutes) were selected .The other variables were kept constant at 18 % NaOH and l/w=8. Tensile strength, tear strength index and folding endurance of hand sheets measured . Factorial experiment and randomized block design was used for statistical analysis and DMRT was used for grouping the means. The results indicate that, application of intermediate cooking intensity produced better pulp than more intense pulping at highest pulping time and temperature. However, more intense pulping produced better folding endurance and pulp prepared at 30 minutes cooking time showed better folding endurance than pulp produced at 20 minutes. The highest tear index was obtain at 185 ْC and 20minutes and lowest at 185ْC and 40 minutes. Results indicate that undamaged fibers will product highest tear index. The highest folding endurance was produced at 175 ْC and 30 minutes and the lowest at 185ْC and 30 minutes .Increasing pulping time reduced tensile index and the highest and lowest tensile index obtained at 20 and 40 minutes pulping time respectively.
