Ali Bayatkashkoli; Mehdi Jamshedzadeh
Abstract
Member joints and furniture designs are very important in the production of these elements and the strength of the structure is affected by both the joints and designs. The performance of the chairs made from poplar wood against the front to back load test and also, mechanical strength of mortise and ...
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Member joints and furniture designs are very important in the production of these elements and the strength of the structure is affected by both the joints and designs. The performance of the chairs made from poplar wood against the front to back load test and also, mechanical strength of mortise and tenon and dowel joints were evaluated and compared. Two types common wooden chairs having side stretcher or without side stretcher, and also the chairs structured by common joints and poly vinyl acetate (PVA) adhesive are evaluated and their maximum strength were measured. The results showed that treatments and intercept treatments were statistically significant with the 95% confidence. Duncan analysis for comparison of the averages showed that maximum load of different treatments can be classified into four category; A; Pattern of side stretcher with mortise and tenon joint (984.5 N), B; Pattern of side stretcher with dowel joint (892.4 N), C; Pattern without side stretcher with mortise and tenon joint (303.3 N), D; Pattern without side stretcher with dowel joint (260.2 N). Since, all treatments showed statistically significant differences, it can be conclude that the maximum strength of the chairs is significantly influenced by the pattern of side stretcher and the other factor is the mortise and tenon joint.
Composite wood products
Habib alah Khademieslam; Mehdei Kalagar
Abstract
In this investigation, tensile and physical properties of polypropylene (as matrix)/wheat straw fiber/paper mill sludge (as filler) composites was studied. The ratio of wheat straw fiber/ paper mill sludge was selected as 40/0, 30/10, 20/20, 10/30 and 0/40 (w/w) were used. Also, for better ...
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In this investigation, tensile and physical properties of polypropylene (as matrix)/wheat straw fiber/paper mill sludge (as filler) composites was studied. The ratio of wheat straw fiber/ paper mill sludge was selected as 40/0, 30/10, 20/20, 10/30 and 0/40 (w/w) were used. Also, for better compatibility between the two phases 3% MAPP as coupling agent was used. Mixing process was done in twin screw internal mixer extruder, and then composite samples were manufactured by injection molding. Result indicated that the tensile modulus of elasticity improved with increasing fillers and also it was observed that the toughness of composite increased when compared to the pure PP, while due to the usage of more paper sludge, these properties was improved. Tensile strength of composite decreased with adding 40% wheat straw fiber, but with addition of sludge tensile strength increased significantly. Adding wheat straw in PP matrix and its hydrophilic properties resulted in the highest rates of water absorption and thickness swelling. However, adding paper sludge and lower amount of lignocellulosic material, and the compatibilizer noticeably decreased the physical properties due to better bonding between two phases.
Mechanical conversion of wood and wooden fittings
Ehsan Ketabi; Amir Lashgari
Abstract
In this study was to evaluate the impact of the truss structure on stiffness and stress distribution in the truss structural members. Made and synchronizes this structures with any Populus_ Nigra lumbers, in finally made 44 truss structure with 11 varying samples and 4 replicates. were used by two joint ...
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In this study was to evaluate the impact of the truss structure on stiffness and stress distribution in the truss structural members. Made and synchronizes this structures with any Populus_ Nigra lumbers, in finally made 44 truss structure with 11 varying samples and 4 replicates. were used by two joint like friction joints was created with Glue stick and dual joint was created with nails to the 4.5 cm and calculate the resistance trusses structures by mechanical testing machine with 12.5 mm/min loading speed and 3.5 KN than mechanical test results showed, Hip Girder truss most resistance stress distribution and were the least impact on the strength and distribution of tension truss structure is significant in 95%. To show the stress distribution on the members, modeling software was AutoCAD, Catia and finite element analysis software was ANSYS. In finally the results show that maximum stress concentration, failure to engage in experimental mode.
Pulp and paper
Pyvand Darabi; Hamideh Abdolzadeh; Ali naghi Karimi; Seeyed Ahmad Mirshokraie; Kazem Doosthoseini
Abstract
In this study capability of acetylated poplar flour in manufacture of high density poly ethylene composite which expose to accelerated weathering, was investigated. The acetylation degrees at medium and zero (control) levels, use of anti- oxidant and duration of weathering were considered as variables ...
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In this study capability of acetylated poplar flour in manufacture of high density poly ethylene composite which expose to accelerated weathering, was investigated. The acetylation degrees at medium and zero (control) levels, use of anti- oxidant and duration of weathering were considered as variables and their effects on discoloration and photodegradation of WPC were investigated. To determine treatments influence on changes and color fade resulting from weathering, samples were tested after o, 250, 2000 hours of weathering. The results indicated that application of acetylated wood flour in WPC can reduce about 25% of weathering discoloration in short time and about 17% in long time. Also it shows that as exposed time of weathering increase Anti oxidant loss its effect. Although in short time it can reduce 12% of weathering color changes. FTIR results show that after 2000 h of weathering all peaks samples had same decrease which mean none of the treatments were useful. But Anti oxidant can reduce depth of weathering.
Chemistry of wood
Mohammad Reza Sabzehparvar; Ahmad Jahan latibari; Shademan Pourmousa
Abstract
Background and Objectives: Plant extractives show unique properties. They impart colors and change the color of wood and generates attractive appearance. Since early days, societies have been utilizing plant extractives in industrial, medical and even as fungicides and biocides. In early times ...
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Background and Objectives: Plant extractives show unique properties. They impart colors and change the color of wood and generates attractive appearance. Since early days, societies have been utilizing plant extractives in industrial, medical and even as fungicides and biocides. In early times this application was based on the professional experiences, but as the sciences were advanced, then the technical and experimental identification and utilization was employed. In general, people look at walnut tree wood and fruit as its economic values. However, scientific research has proved the values of walnut tree extractives. In this study the chemical composition of walnut tree extractives and its variation in two periods of spring and summer as well as the impact of the drying on quantity and quality of the extractive components are investigated.Methodology: Walnut tree leaves from a selected location of an old walnut tree (100 years old) in mountain region of Karaj were collected in spring and summer. One part of the samples was air dried and another portion was used at green moisture condition. Totally four samples were obtained. Ethanol-acetone extraction was according to Tappi T204-05 procedure. The extractive was identified using GC-MASS spectroscopy and the chemical components in the extractives were identified and tabulated. Results: The results revealed that the dried leaves contain fewer chemical compounds compared to green samples which can be an indication that some of the compounds in green sample are volatile and vaporize upon drying. Furthermore, the extractives chemical composition and content varies between spring and summer samples. The major chemical compounds identified were 2-methylneptaline, tri-decan, tetradecan, 2,3-dimethyl naptaline and methylcyclobenzen.Conclusion: The results indicated the seasonal variation of walnut tree extractives. These is also considerable variation in wet and dry samples which can be attributed to the presence of volatile compounds. The odor of walnut leaves is the consequence of existence of such volatile extractives. The absence of some of the compounds in summer samples indicate the seasonal changes of the extractives.
Pulp and paper
Ramin Veisi; Iman Khajeh ali
Abstract
This study and it aim was accomplished on extraction, identification and removal of metallic ions and resins in bleached Bagass pulp by ECF stages. For this purpose, the samples were randomly selected from soda unbleached pulp of Pars mill. The first, pulp flour provided and measured ash and extractive ...
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This study and it aim was accomplished on extraction, identification and removal of metallic ions and resins in bleached Bagass pulp by ECF stages. For this purpose, the samples were randomly selected from soda unbleached pulp of Pars mill. The first, pulp flour provided and measured ash and extractive percent by the TAPPI standards. Then the mineral compounds dissolved in 65% nitric acid and the mineral compounds of pulps identificated by Atomic adsorption method. The results of this study showed that the most of Pb, Cu, Zn ions were in H2O2 bleached pulp, the most of Ni ion in OD(Ep)P stage and the most of Fe ion in unbleached soda pulp. The results showed that OD(Ep)D stage decrease Fe ion and EH stage decrease Ni, Cu and Zn ions in pulps. The results of GC-MS diagram showed that 35 compounds were identified in unbleached soda pulp after cooking, that 1,2-Benzendicarboxylic acid, Hexadecanoic acid, Hexadecan, Octadecan, p-Xylene, 4-Hydroxy-4-Methyl-2-Pantanone,Ethylbenzen and Dodecan were important chemical components in samples. In generally, 17,12 and 14 compounds were identified in EH, OD(Ep)P and OD(Ep)D bleaching stages, respectively, so that, 1,2-Benzendicarboxylic acid and p-Xylene were 2 common and important chemical components in all samples and Octadecan and 9-Dodecanoic acid remove as two components from pulps after bleaching, too. The results showed that EH, OD(Ep)P and OD(Ep)D bleaching stages were very important in bleaching, removal of chemical components and brightness stability of soda pulps.
Kobra Dadmohamadi; Mohsen Mohammadi Achachluei; Mohammad taghi Jafari
Abstract
The aim of this study was to evaluate the effect of cellulose nanofiber treatment on discoloration of historical papers. In this study, two types of cellulose nanofiber suspensions with a concentration of 1% by weight with water and ethanol were prepared. After treatment, the prepared samples were subjected ...
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The aim of this study was to evaluate the effect of cellulose nanofiber treatment on discoloration of historical papers. In this study, two types of cellulose nanofiber suspensions with a concentration of 1% by weight with water and ethanol were prepared. After treatment, the prepared samples were subjected to moist-heat aging according to TAPPI T 544 sp-03 standard and colorimetric, pH, ATR-FTIR spectroscopy and SEM microscopy were performed before and after aging. Examination of ATR-FTIR spectra obtained from the samples showed that the application of cellulose nanofiber treatment does not cause damage to the paper structure. After application of two treatments with cellulose nanofibers, the color of the samples became brighter, but after accelerated aging, the brightness of the samples decreased.The darkening of the color of the samples was caused by their exposure to accelerated aging conditions and the treatment of cellulose nanofibers did not cause discoloration. The pH of the samples increased after application of both types of cellulose nanofiber treatments, but after accelerated aging, the pH decreased slightly.
Aliakbar Ramtin; Behnaz Dadkhahi tehrani; Kazemi Dossthoseini
Abstract
In this study, effects of press temperature and press time on the physical and mechanical properties on the OSB has made from Aspen were investigated. Two levels of press temperature 175ºC and 185ºC and two levels of press time 5 min and 6 min were applied as variables for manufacturing boards. ...
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In this study, effects of press temperature and press time on the physical and mechanical properties on the OSB has made from Aspen were investigated. Two levels of press temperature 175ºC and 185ºC and two levels of press time 5 min and 6 min were applied as variables for manufacturing boards. Mechanical and physical properties such as bending strength, internal bond, water absorption and thickness swelling were measured. results showed that, increase in press temperature and press time causes significant increase on bending strength, internal bond, water absorption and thickness swelling. The best boards were made of press temperature of 185ºC and press time 5 minutes.
Management and Economics wood
Reza Jazayeri; Reza Hajihassani; Sedighe Nazari
Abstract
The main purpose of this study was to evaluate the effect of hydrothermal treatment with boric acid impregnation on some physical and mechanical characteristics and fire resistance of poplar (Populus nigra) and radiata pine (Pinus radiata) wood. In this study, two times of 60 and 90 minutes with two ...
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The main purpose of this study was to evaluate the effect of hydrothermal treatment with boric acid impregnation on some physical and mechanical characteristics and fire resistance of poplar (Populus nigra) and radiata pine (Pinus radiata) wood. In this study, two times of 60 and 90 minutes with two temperatures of 150○C and 180○C were used for the hydrothermal treatment, and boric acid with concentrations of 1, 3 and 5% dissolved in water used for the impregnation treatment. The measurement of the characteristics, including bending strength, impact resistance, volumetric swilling and fire resistance (weight loss due to fire) were done by ASTM-D143, ASTM-D256, ASTM 4446-2002 and ISO 11925 standards, respectively. About fire resistance, 5% boric acid treatment showed the least weight loss due to burning in the wood of two species. As a result of the hydrothermal treatment alone, the fire resistance was even lower than the control. In this regard, the combination of hydrothermal treatment with boric acid treatment resulted in results close to those of hydrothermal with boric acid treatment. Positive effect of hydrothermal treatment on the improvement of dimensional stability, is considered as one of the results of the present study. The temperature of 180○C with a time of 90 minutes reduced the swelling of poplar and radiata pine by about 36.8 and 42%, respectively. Regarding impact resistance, the effect of hydrothermal treatment on the wood of both species and the effect of boric acid treatment on radiata pine wood were negative. Hydrothermal treatment at a temperature of 180○C and with a time of 90 minutes decreased the impact resistance by 28.2% in the wood of both species, and 5% boric acid treatment caused a 13.3% decrease in this property in radiata pine wood.
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.
Babak Mirzaei; Kazem Dosthosseini
Abstract
Lignocellulosic material used as raw material in pulp and paper production due to major chemical alterations produce different waste compounds and composite manufacturing is an area providing the opportunity to utilize such wastes. In order to investigate the feasibility of using papermaking sludge in ...
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Lignocellulosic material used as raw material in pulp and paper production due to major chemical alterations produce different waste compounds and composite manufacturing is an area providing the opportunity to utilize such wastes. In order to investigate the feasibility of using papermaking sludge in composite production, four combinations of wood flour/ papermaking sludge/ high density polyethylene ratio were formulated, then composite panels were made and the physical properties of manufactured panels were evaluated. The content of maleated polyethylene (MAPE) and the polymer was constant 2% and 38% respectively, for all formulations. The results indicated that long term water absorption in particular thickness swelling decreased with increasing sludge content. Furthermore, moisture diffusion coefficient of samples containing 30% sludge and 30% wood flour was more than others. The results revealed that using papermaking sludge can be an alternative option for lignocellulosic raw material.
Pulp and paper
Abas Fakhryan; Fardad Golbabaei; Mohammad mehdi Brazandeh
Abstract
In this research pulp and paper making characteristics of Sequoia sempervirens from Chamestan noor research station were studied. The dry and critical specific gravity of sap wood 0.352 and 0.324, heart wood 0.43 and 0.40, fiber length 2.01 mm. diameter 39.84µm. lumen 33.15µm and cell thickness ...
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In this research pulp and paper making characteristics of Sequoia sempervirens from Chamestan noor research station were studied. The dry and critical specific gravity of sap wood 0.352 and 0.324, heart wood 0.43 and 0.40, fiber length 2.01 mm. diameter 39.84µm. lumen 33.15µm and cell thickness wall 2.89µm were measured as respectively. The amount of cellulose of 52.63%, lignin 35.32%, ext. 6.68% and ash 0.45% were obtained as well. Kraft process was used for pulping. The yield of these pulps in 12% effective alkali were measured as 56% and in 18% effective alkali 39.69% respectively. In 3 hours of cooking time, the tear strength of these pulps 19.74 mNm2/gr and In 2 hours of cooking time 15.22 mNm2/gr respectively were measured.
Management and Economics wood
Habib alah Arab tabar firoz jaei; Ali Reza nezhad; Abdolrahman Hosseinzadeh
Abstract
In this study, durability of Eucalyptus wood(Eucalyptus intertexta R.T.Baker) in both treated with creosote and celcore and untreated to attack by Trametes versicolor (L.ex)L loyd. were evaluated heart wood by the Kolleshal methodes described in DIN 52176, and B.S. 838. The comparison of weight ...
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In this study, durability of Eucalyptus wood(Eucalyptus intertexta R.T.Baker) in both treated with creosote and celcore and untreated to attack by Trametes versicolor (L.ex)L loyd. were evaluated heart wood by the Kolleshal methodes described in DIN 52176, and B.S. 838. The comparison of weight losses of samples were also evaluated and it showed that fungus had no effect on the treated samples but it caused 4% weight loss of natural durability samples. Based on this study, it can be concluded that E. intertexta wood can be classified as a durable wood.
Pulp and paper
Zahra Razmpour; ghasemg asadpour; kermanian hossein; omid ramezani; Seyed Majid Zabihzadeh
Abstract
Efficient approaches to eliminate or neutralize stickies is one of the topics of recent research. In the current study, some of the most conventional chemical and physical strategies in controlling these contaminants were compared. Control of micro-stickies originated from recycling of OCC using some ...
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Efficient approaches to eliminate or neutralize stickies is one of the topics of recent research. In the current study, some of the most conventional chemical and physical strategies in controlling these contaminants were compared. Control of micro-stickies originated from recycling of OCC using some selected physical approaches (washing, washing-flotation, flotation-washing and flotation) and some selected chemical methods by 4 fixing agents (Alum-PAC-pDADMAC-Cationic Starch) at 0.1-0.5-1 % dosing levels based on oven-dry weight of pulp were investigated. Electrical conductivity, TDS, turbidity, dissolved and colloidal substances (DCS) and COD were measured and compared to evaluate the efficiency of each approaches of micro- stickies removal. The results indicated that the lowest value of electrical conductivity and TDS in the physical methods was related to the flotation-washing stage and in the chemical methods was related to cationic starch 1%. The lowest amount of turbidity in the physical methods was observed in the washing and washing-flotation. Besides, the potential of secondary stickies was the lowest in the washing stage, while the flotation method had the highest potential of secondary stickies. Among the different dosing levels of the fixing agents, the lowest level of turbidity and DCS was determined for pDADMAC with 0.1% addition level, and the lowest amount of potential of secondary stickies was observed for Alum with 0.5% dosage. Both in the physical and chemical methods turbidity and DCS in pH4 was more than neutral pH. In the chemical approach with cationic starch dosage at 1% and in the physical method with the washing-flotation stage, the lowest amount of COD was reached
Jafar Ebrahimpour Kasmani; Ahmad Samariha; Alireza Khakifirooz
Abstract
This study aimed to investigate the use of cellulose nanofibers and starch-nano-cellulose and polyacrylamide-nano-cellulose hybrid systems for the replacement of imported long chemical fibers in the production of these papers. In this study, imported long fiber chemical pulp was added to cotton pulp ...
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This study aimed to investigate the use of cellulose nanofibers and starch-nano-cellulose and polyacrylamide-nano-cellulose hybrid systems for the replacement of imported long chemical fibers in the production of these papers. In this study, imported long fiber chemical pulp was added to cotton pulp at 4 levels. Cellulose nanofibers were added to cotton pulp at a 5% level with 1% starch and 0.1% with polyacrylamide. Three levels of cationic starch and three levels of cationic polyacrylamide were also used. From each of the treatments, 60 gm-2 handsheet were made finally the physical, mechanical and optical properties of the paper made from different pulps were compared. The results showed that with increasing nanocellulose individually, compared to imported long fibers, surface smoothness, tensile strength, bursting, tearing of paper increased and air resistance, folding resistance and opacity decreased. Increasing nanocellulose in combination with cationic polyacrylamide increased the paper air resistance and surface area, tensile, burst, tear, and folding strength of the paper compared to imported long fibers, air resistance and opacity. With the increase of nanocellulose in combination with cationic starch, as compared to imported long fibers, surface smoothness, tensile strength, bursting, folding increased but opacity decreased. FE-SEM results also showed that with increasing percentage of cellulose nanofibers, the pores decreased significantly. As a result of the addition of 5% cellulose nanofibers the surface of the paper became smoother and the pores were filled relatively, confirming the results of surface smoothness and air resistance.
Negin Ghahrani; Noradin Nazarnezhad; Omid Ramezani; Ghasem Asadpour
Abstract
Regeneration of cellulose by direct solvent dissolution essentially involves the pretreatment of cellulose with a solvent for swelling the cellulose chains and weakening the cellulose molecules bonds. Aqueous solutions based on sodium hydroxide (NaOH) are low cost, non-volatile, non-toxic, environmentally ...
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Regeneration of cellulose by direct solvent dissolution essentially involves the pretreatment of cellulose with a solvent for swelling the cellulose chains and weakening the cellulose molecules bonds. Aqueous solutions based on sodium hydroxide (NaOH) are low cost, non-volatile, non-toxic, environmentally friendly cellulosic solvent with fast dissolution power at low temperatures. The mechanism of cellulose dissolution in this solvent is not yet fully understood because there are parameters such as temperature, crystallization and degree of cellulose polymerization that affect the solubility of cellulose in the NaOH / urea system. Therefore, this study investigated the effect of kappa factor changes in chlorine dioxide bleaching on the dissolution of OCC recycled pulp on chemical compounds (lignin and hemicellulose) and the degree of polymerization. The results showed that with further reduction of lignin, the dissolution of pulp decreases and this reduction in dissolution is more severe in lignin levels below 3% (reduction from 44% to about 37% dissolution). It seems that during the bleaching process and part of lignin and hemicellulose removal, a part of cellulose with low degree of polymerization is also removed and the average polymerization of the remaining cellulose increases which is more resistant to the phenomenon of pulp dissolution. With increasing kappa factor (to 0.2 and 0.3), there was no significant change in dissolution and hemicellulose. In general, it seems that lignin and the degree of polymerization are not only the effective factors in OCC pulp dissolving and hemicellulose content also can be effective.
Composite wood products
Reza Jazayeri; Habib alah Khademi eslam; Amir Nourbakhsh; Abolfazl Kargarfard
Abstract
In order to survey of possibility of particle board production with «Acacia salicina » the effectiveness of three factor (treatment) included adhesive percentage (in two surface: %9 and %11) temperature degree ( in two surface 1650c and 1750c) pressing time (in three surface: 5/6 and 7 minutes) ...
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In order to survey of possibility of particle board production with «Acacia salicina » the effectiveness of three factor (treatment) included adhesive percentage (in two surface: %9 and %11) temperature degree ( in two surface 1650c and 1750c) pressing time (in three surface: 5/6 and 7 minutes) on mechanical (MOR, MOE, IB) and physical (TS2, TS24) properties were experimented with E.N standard. Therefore 36 boards were prepared for mechanical and physical tests. Data were analyzed with appropriated statistical method. Results indicate %11 adhesive, 1650c temperature degrees and 6 minutes press time is best condition for production. However the results showed more than standard IB (1/24 Mpa ) probably due to its wood chemistry. Therefore this species could be a suitable source to produce particle board
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, ...
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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.
Nano composite
Bardia Sodeifi; Seyed Hassan Sharifi; Noredin Nazarnezhad
Abstract
Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, in order to improve the mechanical and barrier properties of polycaprolactone polymer films, cellulose nanocrystals obtained from alpha-cellulose of cotton linter were added ...
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Development of active and biodegradable packaging is possible by coating biopolymers on packaging materials. In this research, in order to improve the mechanical and barrier properties of polycaprolactone polymer films, cellulose nanocrystals obtained from alpha-cellulose of cotton linter were added to the poly caprolactone composite solution with amounts of (3%, 6%, and 9%), and their structural, mechanical, and barrier properties were investigated. According to the results of the field emission scanning electron microscopy (FESEM) test, the obtained nanoparticles are rod-shaped and have a length in the range of 100 to 150 nm and a diameter of 10 to 50 nm. X-ray diffraction (XRD) confirmed the formation of cellulose nanocrystals. According to the results, by adding cellulose nanocrystals to the composite solution, tensile strength, resistance to water solubility, and impermeability to the water vapor of the films increased, and only the elongation at break reduced. The best mechanical and barrier properties of the nanocomposites were obtained in the presence of 6% cellulose nanocrystals.
Pulp and paper
Sobhan Jahanshahlou; Amir Khosravani; Mehdi Rahmaninia
Abstract
Production of test liner and fluting from old corrugated containers, is one of the most common paper recycling processes in Iran. This type of papers, have high basis weight and also contain significant fine fibrous and non-fibrous materials; hence, the drainage and in addition, the retention of fine ...
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Production of test liner and fluting from old corrugated containers, is one of the most common paper recycling processes in Iran. This type of papers, have high basis weight and also contain significant fine fibrous and non-fibrous materials; hence, the drainage and in addition, the retention of fine materials, are the obstacles these paper mills may encounter. In these cases, usually application of drainage/retention aids, such as nanoparticle systems can be of much help. In this due, colloidal silica and bentonite are the two of the most commonly used nano-particles with polyelectrolytes in papermaking wet-end. Therefore, in this research, the effect of bentonite and silica sol nano-particles on the performance of cationic starch was compared in terms of drainability, retention and strength properties of paperboard from recycled old corrugated containers. The analysis of the particle size for these two nanoparticles showed that although the thickness of bentonite platelets (maximum 22 nm) was less than nanosilica dimensions (less than 50 nm), the effect of bentonite-cationic starch was not significant in terms of retention, against the nanosilica. Regarding the drainability, following dosing of both silica and bentonite, the parameter much improved (up to 186% in the case of nanosilica). On the other hand, application of cationic starch containing systems in paper handsheets resulted in improvement in tensile and tear indices, however, these properties decreased following addition of nano-particles. Also, internal bonding (Scott- type) incredibly increased (up to 354%) by application of cationic starch and nanosilica. At last, generally in the case of OCC furnish, the nanosilica-cationic starch system had a better performance in terms of drainability, retention of fine materials and fiber fines and also strength properties, rather than cationic starch-bentonite.
Physics and anatomy
ali hasanpoor tichi; mojtaba rezanezhad
Abstract
In this study, biometrics, physical and microscopic properties of Ficus carica wood were investigated. Therefore, three healthy Ficus carica trees in Mazandaran province have been selected and cut. Three discs of 5 cm thickness were prepared along the tree (diameter at breast height, 1.9 m height and ...
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In this study, biometrics, physical and microscopic properties of Ficus carica wood were investigated. Therefore, three healthy Ficus carica trees in Mazandaran province have been selected and cut. Three discs of 5 cm thickness were prepared along the tree (diameter at breast height, 1.9 m height and near the crown). In the transverse direction, 2 × 2 × 2 cm test specimens were sequentially taken from the pith to the bark and examined for physical and biometric properties of the fibers. Then the biometric properties of fibers including fiber length, fiber lumen diameter, fiber diameter and cell wall thickness were measured. Physical properties including basic density, oven dry density, longitudinal shrinkage, radial shrinkage and tangential shrinkage were calculated. Microscopic sections of three surfaces (transverse, tangential and radial) of Ficus carica tree was prepared and the anatomical characteristics of the wood of this species were determined precisely and indexed by IAWA. Anatomical studies near the pith and bark of this wood revealed differences. The most important of these differences are the presence of Tyloses in the vessel lumen near the pith and the absence of it in the near bark, homogeneous rays near the bark and heterogeneous rays in the near pith, the mean tangential vessel diameter near larger bark (105 μm) than near pith (70 μm) and wood rays were wider near the bark than near the pith. Also Ficus carica tree was diffuse porous hardwood species, distinct growth ring, Axial parenchyma vasicentric and Banded, Simple perforation plates Intervessel pits alternate and containing prismatic crystals in parenchyma. The results showed that there were significant differences in both the transverse and longitudinal directions of Ficus carica tree in terms of fiber length, fiber lumen diameter, fiber diameter and cell wall thickness. As biometric properties of fibers increased from pith to bark.
Pulp and paper
Jafar Azizi; Omid ramezani; Esmaeel Rasooly; Hamidreza Rudi
Abstract
Cellulosic fines are essential parts of paper making system which impart remarkable effects on the production process parameters and the quality of final product. In this study, properties of fiberfines prepared from three kinds of pulps including Kraft, chemical mechanical (CMP), and recycled (OCC) ...
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Cellulosic fines are essential parts of paper making system which impart remarkable effects on the production process parameters and the quality of final product. In this study, properties of fiberfines prepared from three kinds of pulps including Kraft, chemical mechanical (CMP), and recycled (OCC) were investigated. Required amounts of fines were prepared using Valley Beater apparatus. Then the fines were classified into three categories using dynamic drainage Jar (DDJ): fines passing a 100 mesh remained on 200 mesh (P100/R200), fines passing a 200 mesh remained on a 325 mesh (P200/R325), and fines passing a 325 mesh (P325). Fines properties including dimensional size, special hydrodynamic volume, colloidal charge, alkalinity, turbidity, viscosity, and specific area were examined. The results revealed that PH of fiber suspensions tended alkaline concurrently to the decreasing in dimensional size of fines. Additionally, the colloidal charge of the three types of fines, especially the charge associated with the fines passed through 200 mesh screen and remained on 325 mesh one, showed a different behaviour compared to those in the same classes with the adverse trend to the viscosity variation. Special hydrodynamic volume is consistent with the dimensional size and dimensional ratio with the lowest amount of it observed in the recycled pulp fines. Turbidity has a direct relationship with particles size, homogenous distribution and the specific area of the finesThe results of turbidity related to the fines passed through 200 mesh size showed different behaviour compared to other categories.
Farhad Zeinaly; Ali Kazemi Tabrizi; Amirhosein Jafari Mofidabadi
Abstract
Growing industrial trees is one of the solutions to overcome the wood resources lack. Thus, for efficient investment in wood cultivation, some cases such as annual growth of cultivated species, species adaptation to the climate of the region, adaptation to the soil of the culture site and also the quality ...
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Growing industrial trees is one of the solutions to overcome the wood resources lack. Thus, for efficient investment in wood cultivation, some cases such as annual growth of cultivated species, species adaptation to the climate of the region, adaptation to the soil of the culture site and also the quality of the produced wood and its capability as a raw material used in lignocellulosic industries, must be regarded. One of the recently introduced extremely fast growing poplar cultivars is the “Mofid” hybrid poplar (Populus euphratica Oliv. × P. alba L.). Since the wood and wood-waste produced during the wood mechanical conversion, are used as the main source in the wood-plastic composite production, in this study, the use of 4-year-old Mofid” hybrid poplar wood-flour as filler in the polyethylene wood-plastic production was investigated. Results indicated that the composites with Mofid poplar lignocellulosic filler had acceptable mechanical and physical properties, in a way that they were comparable with the composites containing hardwoods wood-flour filler (control treatment). Results showed that the plasticity and irreversible-strain during applying force were less in poplar filler-composites, so the tensile and flexural moduli were higher than control composites. Results indicated that the use of poplar wood-flour reduced the impact resistance value. Also, among the treatments of 20, 30 and 40% filler, the 30% filler treatment had the highest mechanical properties. All samples had acceptable water-absorption and thickness-swelling characteristics.
Composite wood products
Zahra Jahani lomer; Saeed Reza farrokhpayam; Mohammad Shamsian
Abstract
AbstracIn the past decade, artificial neural networks have been used as a powerful tool for modeling and prediction in many scientific fields. In this study, the feed-forward multilayer Perceptron (MLP) was utilized and trained by back propagation (BP) algorithm with Levenberg-Marquardt numerical optimization ...
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AbstracIn the past decade, artificial neural networks have been used as a powerful tool for modeling and prediction in many scientific fields. In this study, the feed-forward multilayer Perceptron (MLP) was utilized and trained by back propagation (BP) algorithm with Levenberg-Marquardt numerical optimization technique via Matlab software. Temperature of press (°C), mat moisture content (%) and press closing time (sec) were used as inputs, Water absorption (WA2, 24h), thickness swelling (TS2, 24h) and density were the outputs of neural network model. This technique will increase network versatility and decreases the effect of undesirable and weak data. The modeling and prediction was done based experimental data and the forecasting results were compared with real data. The efficiency of these techniques evaluated with statistical criteria of mean square error (MSE), root mean square error, (RMSE) and the correlation coefficient (R2). The results showed this ANN model could accurately describe the water absorption, thickness swelling after immersion for 2 and 24 hours, and density of particleboard
Physics and anatomy
Saeed Mahdavi; masoudreza habibi
Abstract
Growing interest in wood and paper consumption in Iranian industries and forest utilization constraints call for alternative approaches on the exploitation trend. Lately, industrial countries consider utilization of small diameter trees and branches residual wood. European hornbeam with vast coverage ...
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Growing interest in wood and paper consumption in Iranian industries and forest utilization constraints call for alternative approaches on the exploitation trend. Lately, industrial countries consider utilization of small diameter trees and branches residual wood. European hornbeam with vast coverage among the other species in Iran can be an alternative to tree shortage of raw material for the sector. This study showed that the branch fiber dimensions have significantly differed compare to trunk.Average fiber length was measured as 1.76mm for breast height of three trunks and 1.43 mm for two branches samples. Fiber length increased from crown downward to the stump and also from pith to bark, but there was a significant negative correlation between the variations and tree height. Fiber length increased in trees of up to 30 years of age and decreased afterwards. There is no orderly pattern from tree base to the upper branches.Runkel and flexibility coefficients of branch were better than trunk despite of higher fiber dimensions in trunk.
