Management and Economics wood
Eiraj Mansoryar; Alinaghi Karimi; Ghanbar Ebrahimi; Ahmad Mirshokraei; Sohrab Rahimi
Abstract
The water repellency and dimensional stabilization of wood species are important for outdoor uses. In this study, the water absorption and water repelling of poplar wood (Populus Alba) by emulsion of paraffin, Quaternary ammonium and starch, were investigated. Paraffin in three levels of 0%, 3%, 5%, ...
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The water repellency and dimensional stabilization of wood species are important for outdoor uses. In this study, the water absorption and water repelling of poplar wood (Populus Alba) by emulsion of paraffin, Quaternary ammonium and starch, were investigated. Paraffin in three levels of 0%, 3%, 5%, Quaternary ammonium in three levels of 0%, 1.5%, 2.5% and also starch in three levels of 0%, 1% and 2%(by weight) were selected as variables. A set of matched specimens were set aside as control, for making comparison. Results showed that the amount of paraffin had a positive significant effect on water absorption and water repellency that is increasing paraffin would improve these properties. Furthermore, specimens treated with paraffin had better water repellency than control samples. Based on the results, it is claimed that the treatment of 5% paraffin, 0-1.5% Quaternary ammonium and 0-1% starch will bring about water absorption and water repellency in treated specimens to a desired level, without causing any damage to other physical properties of them.
Management and Economics wood
Neda Esmaeili; Maryam Ghorbani; Porya Biparva
Abstract
In this study, the mechanical and biological properties of modified poplar wood with glutaraldehyde and paraffin were investigated. Modification was performed with glutaraldehyde at different concentrations of glutaraldehyde, 5, 10 and 20% using magnesium chloride as a catalyst and then subsequently ...
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In this study, the mechanical and biological properties of modified poplar wood with glutaraldehyde and paraffin were investigated. Modification was performed with glutaraldehyde at different concentrations of glutaraldehyde, 5, 10 and 20% using magnesium chloride as a catalyst and then subsequently with paraffin by vacuum-pressure method. Increasing concentration of glutaraldehyde caused to weight gain and bulking wood cell wall, subsequently reduced paraffin penetration into the porous structure of wood. Biological resistance exposed to white rot fungi and mechanical properties were measured according to the standards EN113 and ASTM D143-94, respectively. Scanning electron microscopic images showed bulking of cell walls and paraffin presence in cell cavities. According to results of TGA, increasing of modification intensity decreased mass loss due to cross linking formation between glutaraldehyde and cell wall polymers. Paraffin at combined modification containing 10% and 20% glutaraldehyde improved significantly the modulus of elasticity. Glutaraldehyde reduced bending strength, but paraffin present in the modified samples improved it. The Glutaraldehyde increased compression strength parallel to grain and hardness that the improvement was more obvious in combined modification. Modification with glutaraldehyde enhanced decay resistance exposed to white rot fungi, and this improvement intensified at the presence of paraffin. Inhibitory influence of chemical modification on wood attacking white rot fungi can be attributed to decreases the wood moisture, bulking of cell walls and blocking cell cavities.
Composite wood products
Ali Akrami; Kazem ِDossthoseini; Ahmad Jahan latibari; Mohammad mehdi Faezipoor
Abstract
In this investigation, the effect of paraffin content and press time and temperature on practical properties especially surface roughness of particleboard is studied. The variables such as paraffin content at 0, 1& 2 percent, press temperature at 170° and 180° C and press time of 4 and 5 ...
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In this investigation, the effect of paraffin content and press time and temperature on practical properties especially surface roughness of particleboard is studied. The variables such as paraffin content at 0, 1& 2 percent, press temperature at 170° and 180° C and press time of 4 and 5 minutes were investigated.
Modulus of rupture, modulus of elasticity, shear strength, water absorption and thickness swelling after 2& 24 hours soaking in water & surface roughness were measured.
The results indicate that there is no significant difference on the influence of paraffin content on either MOR & MOE of the particleboard. But increasing paraffin content decreased shear strength of panels.
However, addition of paraffin reduced water absorption and thickness swelling.
Press temperature had no significant influence on measured properties, but this variables increased surface roughness. Increasing press time, improved MOE, but showed no significant influence on other properties.
