Document Type : Research Paper
Authors
1 Assistant Prof., Wood and Forest Products Science Research Division, Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO) P.O. Box 13185-116, Tehran, Iran
2 Private company in Sanee Wood
3 Assistant Prof., Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran
4 MSc., Wood and Paper Science Research Division, Research Institute of Forests and Rangelands , Iran
Abstract
Effect of thermo-oil process on biological, physical and mechanical performance of produced thermo wood
Abstract
Background and Objectives: Wood has some limitations in properties and applications due to its natural nature, which need to be modified. Wood modification is usually done with different aims and methods. One of the wood modification methods is thermal treatments in order to improvement of dimensional stability and biological resistance. But, it is surely affected on physical and mechanical properties of wood. Wood thermal modification in presence of oxygen causes the oxidation of its chemical structure which leads to decrement of physical and mechanical properties. Therefore, elimination of oxygen in thermal modification can reduce its destructive effects. In current study, the effect of thermo-oil process on the function of white rot fungus has been investigated. Moreover, the effect of this process on engineering properties of birch and pine wood species was evaluated.
Methodology: In this study, two wood species of birch (Betula sp.) and pine (Pinus sp.) cut into the desired timbers. Heat treatment of the prepared timbers was carried out in a cylinder which equipped to the pressure and vacuum system. Also, industrial recycled oil was used for heat treatment of the timbers. The temperature and time treatment were considered 195 °C and 5 hours, respectively. At the end of the process, the used oil was drained into the oil storage tank and the timbers were removed from the cylinder after applying vacuum. In order to investigation of biological resistance as well as physical and mechanical properties (water absorption and swelling, density, mass loss, bending strength, compression strength parallel to the grain and impact strength) test specimens were prepared from the treated and control timbers based on the standard. The SPSS software was used for statistical analysis. The results were statistically analyzed based on a One-Way ANOVA method.
Results: Results revealed that thermo-oil treatment can reduce the functionality of white rot fungus and also its efficiency on physical and mechanical properties of both wood species. Moreover, the results showed that this process improved the physical properties and reduced the mechanical properties, except compression strength parallel to the grain.
Conclusion: Thermo-oil treatment at high temperature causes structural changes of wood and affects its physical and mechanical properties. Also, the structural changes caused by heat treatment can be an effective and inhibiting factor to functionality of white rot fungus on physical and mechanical properties of wood.
Key words: Thermo-wood, thermo-oil, physical and mechanical properties, fungus
Results: Results revealed that thermo-oil treatment can reduce the functionality of white rot fungus and also its efficiency on physical and mechanical properties of both wood species. Moreover, the results showed that this process improved the physical properties and reduced the mechanical properties, except compression strength parallel to the grain.
Conclusion: Thermo-oil treatment at high temperature causes structural changes of wood and affects its physical and mechanical properties. Also, the structural changes caused by heat treatment can be an effective and inhibiting factor to functionality of white rot fungus on physical and mechanical properties of wood.
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