Document Type : Research Paper
Authors
1 Associate 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 Assistant Prof., Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran
3 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
Abstract
Abstract
Background and Objectives: The country's forest resources limitation and prohibition of wood importing have caused several problems in providing lignocellulosic raw materials. Therefore, the use of lignocellulosic waste resources has important role in this field. Particleboard is one of the wood composite products which it is possible to be produced by use of various types of lignocellulosic materials such as agricultural residue. One of the available agricultural wastes in the country is rice husk, which can be used in production of particleboard. However, the use of agricultural lignocellulosic waste has negative effect on engineering characteristic of produced boards. Therefore, the objective of this research is to evaluate the possibility of rice husk application in particleboard production and also obtain an optimal composition of raw material and the other production conditions.
Methodology: Rice husk and industrial wood particles were prepared from the Gilan province and 22 Bahman Company, respectively. The steps of particleboard production included screening, drying, gluing, formation and pressing. In this study, the composition of raw material (100% industrial wood particles, 90% industrial wood particles and 10% rice husk, 80% industrial wood particles and 20% rice husk, 70% industrial wood particles and 30% rice husk) was considered as a variable factor and the other factors including the resin consumption (10% based on dry material of the board), pressing temperature (180 °C), pressing pressure (25 kg/cm2) and pressing time (4 minutes) were considered as fixed factors. A total of 12 laboratory boards with three replications were produced for each treatment. Then, the samples were prepared from each board according to the EN326-1 guidelines. Physical and mechanical tests included measurement of water absorption and thickness shrinkage after 2 and 24 hours of immersion in water, bending strength, modulus of elasticity and internal bonding. The results were analyzed based on a complete randomized design within the framework of a factorial experiment by SPSS software. Duncan's multiple range test was used to compare mean values.
Results: The results of this study showed that the composition of raw materials affects all physical and mechanical properties of manufactured boards, so that increasing of rice husk consumption caused decrease of bending strength, modulus of elasticity and internal adhesion and also increase of water absorption and thickness swelling of 2 and 24 hours of specimens.
Conclusion: In general, the results of current study revealed that consumption of rice husk in small quantity (up to 10% composition of the raw material) can provide boards with acceptable physical and mechanical properties; but higher amounts, lead to a decrease in physical and mechanical properties of the boards. Therefore, small amounts of rice husk can be used as suitable raw materials in combination with industrial wood particles in particleboard industry.
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