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.
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.
