Davood Rasouli; Hossein Yousefi; Mahdi Mashkour
Abstract
In this research, the effect of using nano-zinc oxide (nano-ZnO) as a UV absorbent on the weathering resistance of wood- polypropylene composite was investigated. For this purpose, composite samples containing 0, 1, 2 and 3% nano-ZnO were manufactured using an internal mixer and a laboratory press. ...
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In this research, the effect of using nano-zinc oxide (nano-ZnO) as a UV absorbent on the weathering resistance of wood- polypropylene composite was investigated. For this purpose, composite samples containing 0, 1, 2 and 3% nano-ZnO were manufactured using an internal mixer and a laboratory press. The prepared specimens were exposed to artificial weathering for 1480 hrs (in the periods of 0 ,480, 960 and 1480 hrs). The weathering degradation of specimens was monitored by tensile strength, hardness, colorimetry, Fourier transform infrared spectroscopy (FTIR), and, stereomicroscope tests. Results showed that weathering caused color changes, tensile strength and hardness loss, physical and chemical degradation on the surface of the samples. The use of nano-ZnO partially prevented tensile strength and hardness loss of samples as well as their surface degradation. In general, the use of 2% nano ZnO has been a better performance against weathering than other values.
Hossein Yousefi; Elyas Afra; Davood Rasouli; mahdi mashkour
Abstract
In this study, paper and nanopaper were first produced and then treated with dodecyltriethoxysilane to prepare water repellent cellulose paper and nanopaper were made using dodecyltriethoxysilane. As the result of silane treatment, the hydrophilic surface of paper and nanopaper converted to hydrophobic ...
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In this study, paper and nanopaper were first produced and then treated with dodecyltriethoxysilane to prepare water repellent cellulose paper and nanopaper were made using dodecyltriethoxysilane. As the result of silane treatment, the hydrophilic surface of paper and nanopaper converted to hydrophobic surfaceones. The micrographs of FE-SEM confirmed the nano-scale size of cellulose nanofibers. XPS results showed that the surface of specimens contains silane. With the treatment of silane, the water droplet contact angle increased to 104 and 153 degree in nanopaper and 153 paper, respectivelydegree in paper. Because of this, the surface of treated paper can be regarded as super hydrophobic surface. TGA confirmed that the ash content of treated specimens were higher than those of untreated ones and also it was revealed that the silane treatment made a multi-layers coating on the surface of specimens. The treated specimens showed less water absorption and higher mechanical properties than untreated ones. The silane coupling treatment made water hydrophobic surfaces onof cellulose paper and nanopaper made them water-proof which can led to the development of their applications for outdoorshumid conditions.
Pulp and paper
Sahba Aliniyay Lakani; Elyas Afra; Hossein Yousefi
Abstract
In this research, nano fibrillated cellulose, as a reinforcement nano material and environmentally biodegradable material which has recently attracted the attention of most researchers and paper producers, has been added to chemi-mechanical pulp used for manufacturing of liner board at different charges ...
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In this research, nano fibrillated cellulose, as a reinforcement nano material and environmentally biodegradable material which has recently attracted the attention of most researchers and paper producers, has been added to chemi-mechanical pulp used for manufacturing of liner board at different charges of 5, 20, 50 and 100% in two different levels of freeness. Also, the effect of wet press, one of the the most important processing agents on the properties of paper reinforced with nano fibrillated cellulose, in two levels of press pressure which included 3 and 6 bar, has been investigated. Finally, physical, barrier and strength properties of the papers produced have been measured according to TAPPI test methods. Addition of nano fibrillated cellulose was resulted in improved tensile and air resistance of chemi-mechanical pulp and increasing trend in improving of these properties with increase in press pressure was one of the important achievements of the present research.
Composite wood products
Sayed mohammad javad Mosavi hosseini; Mohammad mehdi Faezipoor; Hossein Usefi
Abstract
The effect of using nanoclay on MDF properties was investigated. Sodium montmorolonit (NA+MMT) was used in three levels of 0, 3 and 6 percent based on dry weight of two resins of urea formaldehyde (UF) and Methylene diphenyl diisocyanate (MDI). Modulus of rupture (MOR), modulus of elasticity (MOE), internal ...
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The effect of using nanoclay on MDF properties was investigated. Sodium montmorolonit (NA+MMT) was used in three levels of 0, 3 and 6 percent based on dry weight of two resins of urea formaldehyde (UF) and Methylene diphenyl diisocyanate (MDI). Modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), thickness swelling (TS) and water absorption (WA) of MDF were measured based on EN standard. Results demonstrated that with the increase of nanoclay in both UF and MDI resins MOR and MOE of MDF increased significantly in such a way that with the use of UF containing 6% nanoclay MOR increased by 33%. Although, IB was significantly affected by UF containing nanoclay, MDI containig nanoclay caused reduction in IB. WA and TS of MDF made from MDI did not show significant variation by increase of nanoclay but those made from UF resin positively affected by adding nanoclay in such a way that MDF made from 3% nanoclay showed 41% loss in TS compared to those made from pure UF.
Pulp and paper
Said mohammad Mazhari mosavi; Saeed Mahdavi; Syed zyaldin Hosseini; Hossein Resalti; Hossein Usefi
Abstract
This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. ...
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This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. Cellulose, lignin, extractive material (acetone solved) and ash were measured 41.66, 16.00, 1.63, and3.46 percent, respectively. Cooking condition was determined as follow: Soda as 16, 18, and 20 percent on the basis of rapeseed dry straw, temperature was set at 175 and 185 Cº, cooking time was set at 40 and 70 minutes, and straw to liquid ratio was set at 1/8. The amount of anthraquinone added to cooking liquor was 0.2%, based on rapeseed dry straw. Using severe cooking factors caused reduction of yield and Kappa number in both methods. Refining was performed on selected pulps in order to reach 35025 (ml,CSF) freeness. The 60 gr/m² hand sheets were made in order to determine mechanical strength and physical properties. Average thickness, density and bulk is measured at 86.4µ, 0.69gr/cm³ and 1.44cm³/gr respectively. Average tear index, burst index, breaking length and tensile indexare measured at 4.6 mN.m²/gr, 3.5 kpa.m²/gr, 7.4km and 72.6Nm/g respectively.
The results showed that however screen yield of rapeseed straw pulp is low but kappa number and mechanical properties of pulp is suitable,compared with the other agriculture residues, so Rapeseed pulp can be used in paper making industries.
Composite wood products
Ali akbar Enayati; Davood Rasooli; Hossein Usefi
Abstract
In this study, plywood manufacture with use of polypropylene as a binder has been studied. The variables were polypropylene in three levels of 80, 120 and 160 g/m2 and maleic anhydride polypropylene coupling agent in two levels of 0 and 4 g/m2 . ureformaldehyde and wheat flour were ...
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In this study, plywood manufacture with use of polypropylene as a binder has been studied. The variables were polypropylene in three levels of 80, 120 and 160 g/m2 and maleic anhydride polypropylene coupling agent in two levels of 0 and 4 g/m2 . ureformaldehyde and wheat flour were used for control samples(120 and 40 g/m2 respectively). Physical and mechanical properties including MOR and MOE (parallel and perpendicular to grain of face layers), water absorption and thickness swelling after 2 and 24 hours of immersion in water were tested. The results showed that maleic anhydride polypropylene coupling agent has significant effect on MOR parallel to grain of face layers. With increase of maleic anhydride polypropylene coupling agent, MOR increased. Polypropylene has positive effect on thickness. With increase of maleic anhydride polypropylene coupling agent, water absorption after 24 hours improved. Although the results revealed improvement in board properties resulted from more polypropylene use but in all properties (except thickness swelling after 24 hours), control samples had better quality than plywood made from polypropylene.
Composite wood products
Hossein Usefi; Ali akbar Enayati; Mohammad mehdi Faezi poor; Sayed hamzeh Sadat nezhad
Abstract
Canola straw as a agricultural residues has been investigated for MDF production. The variables were the steaming time of 2, 5 & 8 minutes and the resin content of 9 and 11 present. Other factors being kept constant. Some of the physical and mechanical properties such as thickness swelling (TS), ...
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Canola straw as a agricultural residues has been investigated for MDF production. The variables were the steaming time of 2, 5 & 8 minutes and the resin content of 9 and 11 present. Other factors being kept constant. Some of the physical and mechanical properties such as thickness swelling (TS), water absorption (WA) modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), were measured. In addition, canola straw fiber properties such as fiber length, diameter and cell wall thickness were determined. The results showed that the optimum condition for MDF production from canola straw is the treatment of 5 minutes steaming time and 11% resin content. All the tested mechanical and thickness swelling properties improved with the increase of steaming time level. Dimensional stability of the MDFs improved as resin content increased. WA and TS values of the produced boards were relatively high because no wax and no depithing were used during the board production. More over, the values of canola straw fiber length, diameter and cell wall thickness are 1215, 28, 7.43 micrometer respectively.
Physics and Mechanical Wood
Sayed hamzeh Sadadt nezhad; Mehdi Tajvidi; Hossein Usefi
Abstract
In this study beech wood steamed specimens were compressed longitudinally to bulk cell wall at three levels of 0, 10 and 15 percent relative to their original length, and some mechanical properties including MOE, MOR, E-value, tensile strength, and tensile strain were measured. The results have shown ...
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In this study beech wood steamed specimens were compressed longitudinally to bulk cell wall at three levels of 0, 10 and 15 percent relative to their original length, and some mechanical properties including MOE, MOR, E-value, tensile strength, and tensile strain were measured. The results have shown that MOE, MOR and E-value as well as strength of specimens decrease with increasing compression but their tensile strain and work at maximum load increase.
Composite wood products
Ali akbar Enayati; Hossein Usefi; Davood Rasoli
Abstract
The effect of Apple pruning wood particles in mixed with industrial wood particles for particleboard manufacturing was studied. One layer laboratory panels with density of 0.6 gr/cm3 with two variables amount of Apple pruning wood particles content (0/100, 15/85, 30/70, 45/55 percent weight of Apple ...
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The effect of Apple pruning wood particles in mixed with industrial wood particles for particleboard manufacturing was studied. One layer laboratory panels with density of 0.6 gr/cm3 with two variables amount of Apple pruning wood particles content (0/100, 15/85, 30/70, 45/55 percent weight of Apple pruning particles/wood particles) and a press time of 5 and 7 min were produced. The physical and mechanical properties of panels were measured. The results showed that the amount of Apple pruning wood particle had significant influence on the most physical and mechanical properties of panels such as MOR, MOE, IB, TS and WA while they were improved as the Apple pruning wood particles increased. The results also indicated that press time had significant influence on the IB and TS of panels and they were increased as the press time increased.
