Composite wood products
Reza Hajihassani; kamyar salehi; Fardad Golbabaei; Hashem Rahamin; meysam mehdinia
Abstract
Background and Objectives: The country's forest resources limitation and prohibition of wood import, have caused several problems in providing lignocellulosic raw materials. Therefore, the use of lignocellulosic waste resources shows important role in this field. Particleboard is one of the wood composite ...
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Background and Objectives: The country's forest resources limitation and prohibition of wood import, have caused several problems in providing lignocellulosic raw materials. Therefore, the use of lignocellulosic waste resources shows important role in this field. Particleboard is one of the wood composite products which can be produced using 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 residues impose negative impact 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 collected from the Gilan province and 22 Bahman Particleboard Company, respectively. The steps in 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 weight 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 swelling 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. Increasing of rice husk consumption decreased the bending strength, modulus of elasticity and internal bonding and also increased the water absorption and thickness swelling after 2 and 24 hours immersion in water.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 substituted raw materials in combination with industrial wood particles in particleboard industry.
Yashar Einollahi; Amir Hooman Hemmasi; Habibollah Khademi Eslam; Esmaeil Ghasemi; Mohammad Talaei poor
Abstract
Considering the increase of environmental pollutant resulted from agglomerating rubbish and wastes containing stable petroleum-based polymers, substitution of these polymers with bio-polymers and solving their problems and defects in the production process as well as the final products is an important ...
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Considering the increase of environmental pollutant resulted from agglomerating rubbish and wastes containing stable petroleum-based polymers, substitution of these polymers with bio-polymers and solving their problems and defects in the production process as well as the final products is an important topic. In this study, the possibility of the production of poly lactic acid (PLA)-rice husk composite with acceptable properties, and also the effect of using flame retardant mineral fillers of aluminum three hydrates (ATH) and magnesium di-hydroxide (MDH) on physical and thermal properties of the produced composite were investigated. Results indicated that the density of PLA-rice husk composite was higher than petroleum-based polymers composites (PP/HDPE-rice husk composites); and flame retardant mineral fillers addition led to an increase in the composite density. Also, flame retardant mineral fillers addition decreased the composite water absorption and thickness swelling, in a way that they were comparable with petroleum-based polymers composites. Results of thermal gravimetric analysis (TGA) showed that flame retardant mineral fillers addition also decreased the temperature of the composite weight loss curve peaks, and the weight loss rate toward temperature rising.
Composite wood products
Abdollah Najafi
Abstract
In this study, chemical treatments of rice husk flour on physical and mechanical properties of rice husk flour / high density polyethylene composites were studied. Rice husk was milled and its flour through the sieve of 60 meshes was selected for using. Initially, dried rice husk flour was subjected ...
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In this study, chemical treatments of rice husk flour on physical and mechanical properties of rice husk flour / high density polyethylene composites were studied. Rice husk was milled and its flour through the sieve of 60 meshes was selected for using. Initially, dried rice husk flour was subjected to chemical treatment with acetic acid and then, was mixed with powder of high density polyethylene at weight ratio of 60% filler loading in an internal mixer. After milling of mixed matreials, samples of composites were made by injection moulding method. Physical and mechanical properties of treated rice husk flour / high density polyethylene composites were compared to untreated composite and a composite including a PE-g-MA coupling agant (MAPE) that were produced in the same method. Dynamic Mechanical-Thermal Analyze (DMTA) of specimens in the temperature range of -50 to +150 ◦C were taken and storage modulus and loss modulus were measured. FT-IR spectra of chemical treatments of rice flour husks were also investigated to what extent changes in the functional groups being studied. Results of FT-IR indicated that the chemical treatment of rice husk led to a change of OH group absorbance on 3436 cm-1 and a peak in the region of 1741 cm-1 related to functional group of C=O. Results of tests also indicated that all of properties in composites including of treated rice husk flour with acetic acid were improved.
Sarveh Hosseinzadeh; Maryam Ghorbani; Porya Biprva
Abstract
This research was conducted to determine the physical properties of poplar wood treated with silica colloidal nanoparticles prepared from rice husk using ash making and alkaline digestion. Test samples were prepared according to ASTM-D1037 standard with the dimension of 2×2×2 cm and then ...
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This research was conducted to determine the physical properties of poplar wood treated with silica colloidal nanoparticles prepared from rice husk using ash making and alkaline digestion. Test samples were prepared according to ASTM-D1037 standard with the dimension of 2×2×2 cm and then were impregnated ina cylinder according to Bethell method applying five concentration levels of soluble colloidal silica nanoparticles (0, 1.2, 1.7, 2.2 and 3.2%). Nanoparticle retention and absorption, density changes, water absorption, and anti-swelling efficiency (ASE) were determined. Nano silica absorption was determined as 119.8, 169.5, 196.3 and 214.7 % corresponding to 1.2, 1.7, 2.2 and 3.2 % nanoparticle addition, respectively. Nano-silica retention in the lowest and the highest treatment level were 1.2 and 9.3%. Results showed that the density increased from 0.37g/cm³ in control samples to 0.40 g/cm³ at the highest level of nano-silica absorption. Water absorption increased by increasing nano-silica absorption. However, dimensional stability of impregnated samples increased. After the longest immersion time, average swelling volume of the sample impregnated with nano-silica was decreased in comparison with the control sample. With increasing nano-silica absorption, anti-swelling efficiency of impregnated samples treated at the 1.2, 1.7, 2.2 and 3.2 % level and immersed for 168h was 36.5, 42.9, 34.7 and 26.8 %, respectively.
