Research Paper
Pulp and paper
Aghdas Sadeghi; Ali Abdolkhani; Yahya Hamzeh; Ahmad Mirshokraei; Alinaghi Karimi
Abstract
In this study the pulping of bagasse using TMAH and EDA as organic bases was investigated and compared to conventional Soda and Soda-AQ bagasse pulping. Resulting pulps properties including Kappa number, reject, screen yield of pulp and optical and mechanical properties of handsheets prepared from them ...
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In this study the pulping of bagasse using TMAH and EDA as organic bases was investigated and compared to conventional Soda and Soda-AQ bagasse pulping. Resulting pulps properties including Kappa number, reject, screen yield of pulp and optical and mechanical properties of handsheets prepared from them were determined and compared. Kappa number of TMAH pulp was considerably lower than others. Also, optical properties of TMAH and TMAH-NaOH pulps were considerably higher than Soda and Soda-AQ reference pulps. As well as, addition of EDA to pulping liquor resulted suitable pulp with better properties compared to Soda pulp. Based on the obtained results, it was concluded that the delignificatiom mechanism of TMAH differ to hydroxide ion from NaOH and probably it improves the delignification rate through increasing of lignin degradation and its solubility.
Research Paper
Management and Economics wood
Sayed mahmood Kazemi; Mehran Jalilvand
Abstract
Wood Plastic Composite as new wood component products is made by wood fiber or powder elements with thermoset or thermoplastic materials. In recent periods of ten years the components have been produced by west industrial countries and as well in UnitedState of America as wood water resistant materials. ...
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Wood Plastic Composite as new wood component products is made by wood fiber or powder elements with thermoset or thermoplastic materials. In recent periods of ten years the components have been produced by west industrial countries and as well in UnitedState of America as wood water resistant materials. Samples of wood plastic and untreated wood specimens of maple and elm were prepared in laboratory. The effects of water, fire and fungus (Trametes versicolor) on the wood samples with using ASTM and EN standards were investigated. The results showed that the highest resistance wood samples against fire was related to wood plastic made by polypropylene and the lowest resistance of wood samples was associated to untreated maple. In the case of floating samples in water, results indicated that increase cross section of wood plastic decreases the rate of water penetration in wood samples. The results of fungal attack in laboratory tests on wood plastic samples showed that component made by 30 % polypropylene and 30% polyethylene and 40% wood fiber is able to resist significantly against rotting fugal.
The weight loss of untreated maple samples against fungal attack was 38.5% that probably is related to being high percent of sugar and starch materials in wood species. There was a difference about 3% of weight loss between natural maple (control) and maple treated by sea water. Therefore, maple is a perishable species in wood durability classification. Heartwood of elm was very resistant to wood rotting fungus and the mean weight loss of wood samples was 3.75%. As a result in wood classification this wood specie is very durable. Appling of sea water only 0.5% increased wood resistance to fungal activity. The results of fungus attack on wood plastic showed this wood product is very resistant and during 6 weeks incubation only 3.14% of its weight was decreased.
Research Paper
Delaram Drakhshandeh; Behbood Mohebi; Saeed Mahdavi
Abstract
This research was carried out to study the influence of acetylation on paper dimensional stability. Specimens from printing paper and Texon paperboard were oven dried and then treated with acetic anhydride at 120°c for 30 and 60 min without catalyst. Acetylated papers were soaked in water for 2 and ...
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This research was carried out to study the influence of acetylation on paper dimensional stability. Specimens from printing paper and Texon paperboard were oven dried and then treated with acetic anhydride at 120°c for 30 and 60 min without catalyst. Acetylated papers were soaked in water for 2 and 24 h. Afterwards, bulking effect of the acetylation and thickness swelling of the specimens as well as anti-swelling-effect (ASE) were determined in the treated specimens.
Results revealed that the bulking of the specimens were increased by reaction time. However, in case of Texon, it was slowed down after 30 min of the reaction time. The thickness swelling of the treated specimens was significantly reduced after soaking in water for 2 and 24 h compared with untreated samples. As it was expected the acetylation increased ASE in Texon and the printing papers.
Research Paper
Composite wood products
Abdolah Najafi; Mehdi Faezipoor; Habibalah Khademi eslam; Saeid Kazemi; Amir homan Hamasi
Abstract
In this study flexural properties Wood-plastic composites(WPCs), the composites made from high density polyethylene(virgin, recycled and mix of them) and four types lignocellulosic fillers (wood sawdust, sanding of MDF, particleboard sawdust and rice hull) at %60 by weight fiber loadings were manufactured ...
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In this study flexural properties Wood-plastic composites(WPCs), the composites made from high density polyethylene(virgin, recycled and mix of them) and four types lignocellulosic fillers (wood sawdust, sanding of MDF, particleboard sawdust and rice hull) at %60 by weight fiber loadings were manufactured using a dry blend/hot press method. Nominal density and dimensions of the panels were 1g/cm3 and 35Î35Î1cm, respectively. After conditioning, flexural properties of the panels including flexural modulus and flexural strength were determined. The results show the flexural modulus and strength wood plastic composites containing sanding MDF and particleboard sawdust were higher than those made from other fillers. The flexural modulus and strength were affected by kind of high density polyethylene (virgin or recycled
