Composite wood products
Masoudreza Habibi
Abstract
The purpose of this study was to use of Hemp stalks in particleboard production. Mixtures of Hemp stalk and Eucalyptus wood at the ratios of 0:100, 50:50, 100:0 were used. Also two resin content of 8 and 10% (based on oven dry particle) and 2 press times of 3 and 4 minutes were employed for the production ...
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The purpose of this study was to use of Hemp stalks in particleboard production. Mixtures of Hemp stalk and Eucalyptus wood at the ratios of 0:100, 50:50, 100:0 were used. Also two resin content of 8 and 10% (based on oven dry particle) and 2 press times of 3 and 4 minutes were employed for the production of laboratory particleboard. Physical and mechanical properties including thickness swelling after 2 and 24 hours soaking in water, modulus of rapture, modulus of elasticity and internal bonding were measured data were statistically analyzed. It was observed that the increase in Hemp stalk particles in the mixture resulted in increasing of bending properties (bending strength and modulus of elasticity) and thickness swelling after 2 and 24 hours water soaking. Also the results showed that increase in Hemp stalk particles in the mixture resulted in reduction of internal bonding. As expected, physical and mechanical properties of particleboard improved with increasing resin content. Modulus of elasticity and thickness swelling after 24 hours water soaking were improved with increasing of press time. In general, comparing the produced board mechanical properties with standard of Iran requirements, the board produced using 100% and 50% Hemp stalk, 8% resin content and 3 minutes press time showed that optimal properties. Although the physical properties of the boards did not meet the standard values, the reason for this could not be due to the lack of use of paraffin.
Physics and anatomy
Nooshin Toghraie
Abstract
One-year seedlings of five species of eucalypt: E. camaldulensis, E. microtheca, E. viminalis, E. globulus and E. gunnii were treated for 14 weeks in growth season, tilting a branch to c. 60° in every successful ones. We investigated the anatomical features of stems wood after 15 days and every 2 ...
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One-year seedlings of five species of eucalypt: E. camaldulensis, E. microtheca, E. viminalis, E. globulus and E. gunnii were treated for 14 weeks in growth season, tilting a branch to c. 60° in every successful ones. We investigated the anatomical features of stems wood after 15 days and every 2 weeks according to IAWA list of features afterwards.The results showed that tilted stems formed more tension wood in the form of gelatinous fibers than straight (untreated) ones. The formation of gelatinous fibers was considered to be closely related to tension wood formation. The formation of gelatinous fibers was considered to be closely related to tension wood formation. Excluding E. globulus, all the other species formed growth eccentricity and tension wood. Although the significant differences between the species and between different locations in the branches, there were no significant differences between the percent of tension wood among the species studied.
Chemistry of wood
milad tajik; ramin vaysi; majid kiaei
Abstract
This research was carried out to identification and comparison of organically chemical component in the wood / bark extractives Eucalyptus camaldulensis. Three healthy trees were cut down from Nowshahr forest and samples were converted into the wood flour. The extractives was prepared with acetone solvent ...
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This research was carried out to identification and comparison of organically chemical component in the wood / bark extractives Eucalyptus camaldulensis. Three healthy trees were cut down from Nowshahr forest and samples were converted into the wood flour. The extractives was prepared with acetone solvent according to TAPPI standard, then transfer to the ballon and then the BSTFA catalyst was added and transfer to the GC / MS injections. Identification of components was done according to the retention time curve, calculation of Kovats correlation and Adams table. Out of 13 components in the bark of Eucalyptus and 18 components in that wood, 2 constituents such as Bis (2 - ethyl hexyl) phthalate and hexadecanoic acid was detected as the same. The most important of chemical component in the bark is (2 _ ethyl hexyl) phthalate (98.72 %). 2 - Pentanone (57.41 %) was important component in the eucalyptus wood .
Salehe Nazari; Noraldin Nazarnezhad; Mohammad Ali Ebrahimzadeh
Abstract
Plants are a rich source of phenolic compounds as natural antioxidants. Antioxidants are the main factors in neutralizing free radicals and prevent the spread of diseases and destruction of many foods. These compounds are extractable from the bark of Eucalyptus camaldulensis and Pinus sylvestris trees. ...
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Plants are a rich source of phenolic compounds as natural antioxidants. Antioxidants are the main factors in neutralizing free radicals and prevent the spread of diseases and destruction of many foods. These compounds are extractable from the bark of Eucalyptus camaldulensis and Pinus sylvestris trees. The purpose of this study was to evaluate the antioxidant properties and total phenolic and flavonoids of Eucalyptus and pine wood bark. After preparation of the bark, ethanol extracts were extracted using soxhlet extractor. First the amount of total phenol and flavonoids of the extract was measured. Then to evaluate antioxidant properties of the extracts, four methods include Diphenyl Picryl Hydrazyl, reducing power; nitric oxide and metal chelating activity were used. The results showed that total phenol and flavonoid content, in eucalyptus bark was higher than pine. Test results to trap free radicals of diphenyl Pykryl Hydrazyl showed that 50% inhibitory concentration of ethanol extract of the Eucalypt and Pine bark values as 3.02 and 15.77 micrograms per milliliter, respectively. Also, in reducing power test, absorption rate for eucalyptus bark extract was higher than the pine. In nitric oxide trap test, 50% inhibitory concentration in ethanol extract of eucalypt bark was measured as 2.41 and in pine extract was 22.75 micrograms per milliliter. Furthermore, the results of Fe2+ chelating ability of ethanol extract of eucalyptus and pine bark at a concentration of 100 micrograms per milliliter inhibited 37 and 97/18 percent respectively. Ethanol extracts of the eucalypt and pine bark in four case study tests, showed an acceptable antioxidant activity. Thus, these compounds can be regarded as good sources ofnatural antioxidants.
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.
Composite wood products
masoudreza habibi; Hossein Hosseinkhani; Saeed Mahdavi; Sayed javad Sepidehdam
Abstract
In this study, particleboard was produced by Eucalyptus and Poplar wood mixture. Variations of this study were as follow: - Combinations of Eucalyptus and Poplar wood were (%100 , %0) , (%66.5 ,% 33.5) , (%33.5 ,% 66.5) and (%0 ,% 100) respectively. ...
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In this study, particleboard was produced by Eucalyptus and Poplar wood mixture. Variations of this study were as follow: - Combinations of Eucalyptus and Poplar wood were (%100 , %0) , (%66.5 ,% 33.5) , (%33.5 ,% 66.5) and (%0 ,% 100) respectively. - Resin content ( %8 and %10) Physical and mechanical properties of boards such as MOR, MOE, IB TS2 and TS24 were tested according to EN standard. The effects of raw materials combinations on bending properties were significant. Maximum of MOE and MOR were observed in %66.5 of Poplar wood and % 33.5 of Eucalyptus wood. As expected, Physical and mechanical properties of boards were improved by increasing of resin content. Results indicated that TS2 and TS24 were increased with increasing of Poplar wood in combinations. Also the minimum of these properties were obtained in combinations of Eucalyptus and Poplar wood, %100, %0 respectively.
Composite wood products
Amir Nourbakhsh; Abolfazl Kargarfard
Abstract
In this study the effect of resin content and press time of particleboard from Date palm residues, Eucalyptus camaldulensis, Tamarix residues and prosopis (Mesquite) producted were investigated in southern of Iran.Variable factors as resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) ...
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In this study the effect of resin content and press time of particleboard from Date palm residues, Eucalyptus camaldulensis, Tamarix residues and prosopis (Mesquite) producted were investigated in southern of Iran.Variable factors as resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) and total of 27 boards were fabricated. Other factors such as type of resin (UF), hardener content (2 percent) type of hardener (NH4Cl) press closing time (4.5 mm/sec.), board density (0.7 gr/cm3) press pressure (30 kg/cm2) and press temperature (160 °C)were held constant.All boards were tested according to DIN-68763 standard. The factorial experimental design at completely random test was used. The results of this study could be summarized as follows:Increasing the resin content from 9 to 11 percent, MOE and IE and decreased thickness swelling after two and 24 hours immersion in water. The results revealed that the polymerization of resin and wood is better at 11 percentresincontentand6 minutes of press time.
Composite wood products
Hossein Hosseinkhani; Abdolrahman Hosseinzadeh; Fardad Golbabaei; Amir Nourbakhsh; Nayeralsadat Sadraei; masoudreza Habibi
Abstract
In this study, the effect of board type, press time and resin content on the strength of particleboard have been evaluated. The boards made for this study contained bagasse and logging residues of Eucalyptus wood particles at a 50 to 50 ratio and employed Urea formaldehyde (UF) resin as the binder. Variable ...
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In this study, the effect of board type, press time and resin content on the strength of particleboard have been evaluated. The boards made for this study contained bagasse and logging residues of Eucalyptus wood particles at a 50 to 50 ratio and employed Urea formaldehyde (UF) resin as the binder. Variable factors are as follows:- type of board; single layer, three layer- press time; 5 , 6 , 7 , minutes- resin content; 9 , 10 , 11 percentThree boards' were manufactured for each combination of variables. Samples of all the boards made were tested by the methods described in DIN 68763 standard to obtain mean values of bending strength, and internal bond strength (LB). In addition samples of each type of board were tested for thickness swelling after immersion in water for 2 hours and 24 hours respectively.The results of this study show clearly that three layer particleboard has significantly higher bending strength than single layer, but single layer boards have better properties from the physical aspect.
Increasing the content of U.F resin from 9 per cent to 10 per cent was found to reduce the thickness swelling, and tended to improve the strength properties of the board, in both single layer and three layer boards. Press time has significant effect on bending strength and I.B Highest MOR and MOE were observed on three layer board pressed for 7 minutes.
Abdolrahman Hosseinzadeh; Habialah Arabtabar; Fardad Golbabaei; Hossein Familian; Nayeralsadat Sadraei; Masoudreza Habibi
Abstract
Eight-nineteen-year-old trees from Eucalytus steriaticalyx from Dehnow experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. From each tree, 10 cm thick cross-sectional discs at several different heights (3 meters intervals) were ...
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Eight-nineteen-year-old trees from Eucalytus steriaticalyx from Dehnow experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. From each tree, 10 cm thick cross-sectional discs at several different heights (3 meters intervals) were cut and together with remaining boles then transferred to the Alborz Research Center-Karaj for laboratory studies. The laboratory studies included determination of physical, anatomical and mechanical properties as well as chemical compositions of wood.The mechanical properties were evaluated on the ASTM samples for air-dry and green conditions. The following conclusions were drawn from this study:E. steriaticalyx from one site in southern region of Iran has an average specific gravity of 0.935, fiber length of 0.881 mm, fiber diameter of 16.063 m, lumen diameter of 4.465 m, cell wall thickness 5.789 m, cellulose content of 47.07 percent.It was found that the mean values of modulus of rupture, modulus of elasticity and compression strength-parallel to grain tested at green condition were 67.35 MPa, 8649 MPa and 35.36 MPa and air- condition were 117.53 MPa, 13397 MPa and 72.31 MPa respectively.Data are also presented on other mechanical properties such as impact strength, nail withdrawal cleavage and etc.
Chemistry of wood
Abdolrahman Hosseinzadeh; Abbas Fakhryan roghani; Fardad Golbabaei; Nayeralsadat Sadraei
Abstract
Eight-nineteen-year-old trees from Eucalyptus camaldulensis from De- hnow experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. Form each tree, 10 cm. thick cross-sectional discs at several different heights (3 meters intervals) ...
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Eight-nineteen-year-old trees from Eucalyptus camaldulensis from De- hnow experimental Plantation located 160 Km. South west of Shiraz were selected randomly and fell two from each of the four blocks. Form each tree, 10 cm. thick cross-sectional discs at several different heights (3 meters intervals) were cut and together with remaining boles then transferred to the Alborz Research Center-Karaj for laboratory studies. The laboratory studies included determination of physical, anatomical and mechanical properties as well as chemical compositions of wood.The mechanical properties were evaluated on the ASTM methods for air-dry and green conditions. The following conclusions were drawn from this study:E. camaldulensis from one site in southern region of Iran has an average specific gravity of 0.806, Fiber length of 1.043 mm, fiber diameter of 15.38 mm, lumen diameter of 4.84 mm, cell wall thickness 5.29 mm, cellulose content of 42.5 percent. It was found that the mean values of modulus of rupture, modulus of elasticity and compression strength-parallel to grain tested at green condition were 81.19 MPa, 10887 MPa and 67.39 MPa respectively.Data are also presented on other mechanical properties such as impact strength, nail withdrawal cleavage and etc.
