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.
Composite wood products
Abolfazl Kargarfard; Amir Nourbakhsh
Abstract
AbstractThe objective of the present study was the utilization of cotton stalk residues for medium density fiberboard production. MDF was produced applying Three press temperatures (170, 180, and 190 oC ) and three pressing times (3,4 and 5 minutes) were used to produce medium density fiberboard (MDF) ...
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AbstractThe objective of the present study was the utilization of cotton stalk residues for medium density fiberboard production. MDF was produced applying Three press temperatures (170, 180, and 190 oC ) and three pressing times (3,4 and 5 minutes) were used to produce medium density fiberboard (MDF) from cotton stalks fibers. The properties of the laboratory boards were measured and the results are analyzed applying factorial experiment and randomized design. In case, the statistical difference was observed between the averages, then Duncan Multiple Range Test was used for grouping the averages. The results showed that as either press temperature or press time is increased, the modulus of rupture of the of the boards was significantly improved and the highest value was reached when 190 oC press temperature and 5 minutes press time was applied. The internal bonding of the boards was significantly higher when 180 oC press temperature was applied. The effect of press temperature on thickness swelling after 2 and 24 hours immersion in water was statistically significant and the lowest values were obtained when 190 oC press temperature was used. The results of this study indicated that the cotton stalks can be considered as a potential raw material for medium density fiberboard production and the properties of the boards meets the EN requirements.
Pulp and paper
Mehrnoosh Tavakoli; saraeyan ahmad reza; hossein resalati; ali ghasemian
Abstract
The present study was carried out aiming to investigate the effect of using Deinked Mixed Office Waste Pulp (MOW) on the properties of Alkaline Peroxide Mechanical Pulp (APMP) from cotton stalk. APMP pulps was prepared using chelating agents such as Na2SiO3 and DTPA (control sample) and without ...
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The present study was carried out aiming to investigate the effect of using Deinked Mixed Office Waste Pulp (MOW) on the properties of Alkaline Peroxide Mechanical Pulp (APMP) from cotton stalk. APMP pulps was prepared using chelating agents such as Na2SiO3 and DTPA (control sample) and without these agents in two-stage pulping withL/Wratio 6:1(ml/g), 20 minutes impregnation time at 70 0Cfor firststage, 60 minutes impregnation at 75 0Cfor second stage. Also, pulp was preparedfrommixed office waste paper, whichweredeinked with conventional flotation and then each pulp was separately refined up to about 300 ml CSF. The handsheets were made from control sample pulps, APMP without chelating agents, MOW deinked pulp and mixing with 10%, 20% deinked pulp with control APMP. Physical and mechanical properties were determined using TAPPI standard methods. Deinked MOW pulp had the maximum values of density, brightness, strength properties and APMP pulp without chelating agents had the minimum values. Among mixed pulps, APMP pulp containing 20% deinked MOW pulp showed the maximum value of density, brightness, burst index and tear index.
Pulp and paper
alireza shakeri; monireh imani; farshad miraki
Abstract
Cellulose is one of the most abundant natural biopolymer on earth is renewable, biodegradable and non-toxic. Micro and Nano-scale cellulose fibers and their applications in composite materials due to their high strength and stiffness combined with low weight, biodegradability and renewability has attracted ...
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Cellulose is one of the most abundant natural biopolymer on earth is renewable, biodegradable and non-toxic. Micro and Nano-scale cellulose fibers and their applications in composite materials due to their high strength and stiffness combined with low weight, biodegradability and renewability has attracted considerable attention. In this study, Micro-crystalline cellulose (MCC) of the skin of the cotton plant by acid hydrolysis in 2N hydrochloric acid to acid ratio of dough the Nano-crystalline (NCC) were prepared by chemical methods. Effect of hydrolysis conditions on properties such as the crystallinity and crystal size Micro and Nanocrystals cellulose with measurement range into the infra-red February (FT-IR), X-ray diffraction (XRD) were reviewed and The shape and size of the samples by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were studied. Fiber analysis using x-ray showed that increasing the amount of acid in the crystallinity of cotton cellulose Micro- crystalline increase the crystal size does not change Lower moisture uptake. Cotton cellulose Nanocrystals and crystal size greater than Micro- crystalline size were reported.
Chemical conversion
mahdiye mazandarani; ali ghasemian; ahmadreza Saraeyan; mahdi mashkour; SeyedRahman Jafari Petroudy
Abstract
In the present study, preparation of cotton stalk (Sahel variety) as one of the common agricultural residues was studied through three stages as Soda-AQ chemical pulping, delignification and alkaline treatment, aiming for the production of cellulose nanocrystal. In order to identify the optimum condition ...
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In the present study, preparation of cotton stalk (Sahel variety) as one of the common agricultural residues was studied through three stages as Soda-AQ chemical pulping, delignification and alkaline treatment, aiming for the production of cellulose nanocrystal. In order to identify the optimum condition for the preparation of cellulose nanocrystal, acidic hydrolysis of the produced alpha-cellulose was done using 64% sulfuric acid, 25, 35 and 45 minute as time and at 35, 45 and 55 degree centigrade as temperature. Atomic Force Microscopy (AFM), X-Ray Diffraction, and Dynamic Light Scattering (DLS) were used to identify the quantitative and qualitative properties of cellulose nanocrystals. AFM micrographs showed that more severe condition of the treatments decreased the thickness of the cellulose nanocrystals. XRD results also demonstrated that the preparation stages of alpha-cellulose as well as acidic hydrolysis treatments much effectively increased the degree of crystallinity. DLS results indicated that 98.7 percent of the produced nanocrystals under the condition of 55 degree centigrade and 45 minute were in the range of 18-95 ηm, whose highest abundance was in the range of 18-39 ηm. Thus, the mentioned condition were determined as the best and optimum condition for the production of cellulose nanocrystal from cotton stalk cellulose.
Composite wood products
mahdi abasyan; asghar omidvar; mahdi mashkour; zinat farhadi
Abstract
This study seeks to investigate the possibility of producing polypropylene composite- cotton stalk flour with various percentages of cotton stalk flour. Determining the best treatment in terms of physical and mechanical properties and exploring the effect of using cotton stalks in the production of the ...
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This study seeks to investigate the possibility of producing polypropylene composite- cotton stalk flour with various percentages of cotton stalk flour. Determining the best treatment in terms of physical and mechanical properties and exploring the effect of using cotton stalks in the production of the composites were among the major objectives of this study. Six treatments consisting of Polypropylene, 40, 55 and 70 percent level of cotton stalks and two fillers (cotton stalks with and without barks) were developed. Maleic anhydride modified polypropylene (3% wt) was applied to each treatment. The mixing and granulation of the plastic and cotton silk flour was carried out using twin screw extruder model 4815. After preparing and shearing of samples, the mechanical properties of composites including tensile strength, rupture modulus and elasticity modulus were calculated in accordance with D-6109 and ASTM D-7031 standards. In addition, water absorption and thickness swelling tests were performed according to D-570-98 standard. The results showed that an increase in the flour of cotton stalk reduced the tensile strength and rupture modulus on the one hand, and increased the bending elasticity modulus on the other hand. In terms of the performance of the filler, there was a significant difference between values of rupture modulus and elasticity modulus at 95% level whereas this difference was not significant for tensile strength. Moreover, this difference was significant for values of water absorption and thickness swelling. The maximum tensile strength belonged to T4 with 40 percent of cotton stalk bark fibers.
Fardad Golbabaei; Hossein Hosseinkhani; Reza Hajihassani; Arash Rashnv
Abstract
The main objective of the production of cement - wood products or mineral-bounded composite panels is to combine the mineral components of lignocellulosic materials such as wood and organic particles with inorganic binders such as cement, plaster, etc. Wood cement products which are presently produced ...
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The main objective of the production of cement - wood products or mineral-bounded composite panels is to combine the mineral components of lignocellulosic materials such as wood and organic particles with inorganic binders such as cement, plaster, etc. Wood cement products which are presently produced in most countries possess desirable functional properties such as good weather ability, resistance to atmospheric, biological agents and fire and are lighter weight as compared with other building materials, and provides improved dimensional stability. The flat panels using conventional presses can be produced, and also other products such as concrete blocks, bricks and pieces of different forms can be produced using appropriate frames. Large wood cement- based panels are widely used in construction of residential and commercial buildings. In this research, with respect to the availability of lignocellulosic material (agricultural residues such as rice straw, wheat straw, cotton stalk) in various areas (Gilan, Mazandaran and Golestan)) and the additive material (as calcium chloride), boards with similar structural was produced. Mechanical strength values including static bending strength, modulus of elasticity and elastic bending strength were measured. MSTATC based computer package was used to analyze the data. In terms of the maximum load strength, wood cement board made of poplar wood as the control boards (4.4146 MPa) had the highest mechanical strength followed by cotton stalks (2.463 MPa), wheat straw (1. 6776 MPa) and rice straw (0. 8622 MPa), respectively. In general, the study has indicated the suitability (given the appropriate ratio) of the agricultural residues in construction of wall and warehouse in farm lands.
Hossein Shob chary; Ahmad reza Saraeyan; Ali Ghasemian
Abstract
This study was conducted to investigate the properties of cotton stalks APMP pulp. APMP prepared from chipped cotton stalks. the pulps were prepared separately from debarked and bark containing stalks using three two-stage treatments.Sodium hydroxide charge as a constant level of 4% and hydrogen ...
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This study was conducted to investigate the properties of cotton stalks APMP pulp. APMP prepared from chipped cotton stalks. the pulps were prepared separately from debarked and bark containing stalks using three two-stage treatments.Sodium hydroxide charge as a constant level of 4% and hydrogen peroxide at three levels of 0, 1 and 2% were used in to two-stages, sodium hydroxide as a constant level of 2% and hydrogen peroxide at three levels of 2, 3, 4% were applied. Other conditions of pulping was time's of 20 min for first stage and 100 min for second stage, temperature 70°C and l/w:6:1 as fixed factors considered. Pulp yield determined after neutralization and defiberation. All the pulps were refined up to 300 (ml, CSF) freeness and handsheets were made, then and properties of papers measured using TAPPI standards. Results showed that the pulp yield and brightness was higher in free-bark compared to bark-containing conditions. Also paper produced in free-bark condition with cotton stalks core, resulted the higher tensile and burst indexes and higher breaking length compared to whole cotton stalk.While tear index didn’t show significant difference.Generally, caliper and bulk rates were high in total treatments (free-bark and bark-containing conditions) from cotton stalk APMP process.
Physics and Mechanical Wood
Shamohammad Amiri
Abstract
Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl ...
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Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl coefficient were calculated at 34.28, 67.14 and 48.93 respectively.Chemical composition of cotton stalk was determined at 47.83%cellulose, 21.66% lignin, 2.13% alcohol-acetone extractives and 2.83% ash.Soda pulping at following variables was investigated. Three levels, of cooking temperature (140, 160 and 180 degree Celsius), three cooking time (30, 40 and 50 minutes) and raw material condition (normal and debarked stalks). Active alkali of 20% (based on NaOH) and liquor to wood ratio of 5: 1 were kept constant for all soda cooks. The optimum combination of variables160 degree Celsius I temperature, 40 minutes time and debarked raw material. The yield and kappa no. of pulp obtained at this cooking condition was 50.4% and 89.15 respectively.
Composite wood products
Abolfazl Kargarfard; Amir Nourbakhsh; Fardad Golbabaei
Abstract
The purpose of this study was to investigation the utilization of cotton stalk and Eucalyptus wood (E. Camaldulensis) in particleboard production. Experimental boards were produced with using of 0, 25, 50 and 75% cotton stalk particles with Eucalyptus wood particles, press time at 3, 4 and 5 minutes. ...
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The purpose of this study was to investigation the utilization of cotton stalk and Eucalyptus wood (E. Camaldulensis) in particleboard production. Experimental boards were produced with using of 0, 25, 50 and 75% cotton stalk particles with Eucalyptus wood particles, press time at 3, 4 and 5 minutes. 36 boards were produced and physical & mechanical properties of their tested and analyzed. The results indicated that the modulus of rupture (MOR) and modulus of elasticity (MOE) of boards with increasing of cotton stalk particles were modified significantly, and MOR and MOE of boards produced with 75% cotton stalk and 25% of Eucalyptus wood particles were maximum. The results indicated that the internal bonds (IB) of boards with increasing press time were improved and the IB of boards produced at 5 minutes of press time was maximum, in order to the lowest of thickness swelling (T.S) of boards observed in same conditions. However thickness swelling of boards produced with 50 and 75% cotton stalk were higher than other treatments, significantly. The results of this study showed that in conditions that apply of species with high density such as Eucalyptus is unavoidable in particleboard production. Between 50 to 75 percent of wood materials that utilized in particleboard production, can be obtained from cotton stalk and with apply of their in particleboards can be produced particleboards in standard levels.
