Composite wood products
Alireza KHAKIFIROOZ; Ahmad Samariha; Hirsa Jouya
Abstract
Background and objectives: Given the increasing use of nanocomposites in various industries, improving the mechanical and physical properties of these products is of particular importance. Nano calcium carbonate as an effective reinforcing agent can help improve the performance of poplar flour and recycled ...
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Background and objectives: Given the increasing use of nanocomposites in various industries, improving the mechanical and physical properties of these products is of particular importance. Nano calcium carbonate as an effective reinforcing agent can help improve the performance of poplar flour and recycled polypropylene nanocomposites. This research investigates the effect of the dosage of calcium carbonate nanoparticles in the nanocomposite mixturr on the mechanical properties of these nanocomposites. The main objective of this research is to evaluate the effects of the size and amount of nano-calcium carbonate on the modulus of elasticity, tensile strength, and other mechanical properties of nanocomposites. The results of this study can help develop lightweight and durable products in the packaging, automotive, and other industries, and provide a solution for the optimal use of recycled materials.Methodology: For this purpose, polypropylene (at three levels of 50, 60, and 70%), poplar wood flour (at three levels of 30, 40, and 50%), nano calcium carbonate (at four levels of 0, 1, 2, and 3% by weight), and maleic anhydride grafted polypropylene at a fixed level of 3% were mixed using a twin-screw extruder, and standard test specimens were made using injection molding. Then, mechanical properties including tensile and bending strength, tensile and bending modulus, impact strength, and hardness were measured.Results: The results related to the F-value and significance level showed that the effect of wood flour content on mechanical properties including tensile and bending strength, tensile and bending modulus, impact strength, and hardness was significant at a confidence level of 95%. Additionally, the effect of nano calcium carbonate on tensile and bending strength, bending modulus, and hardness was also significant at 95% confidence level, while bending modulus and impact resistance were not significant at this level. The interaction effect of flour amount and nano calcium carbonate was not significant on all strength at the 95% confidence level.Conclusion: The results of this research show that increasing poplar wood flour from 30 to 50 percent has a significant effect on the mechanical properties of nanocomposites, especially increasing tensile and bending strength, tensile and bending modulus, and hardness. This improvement is due to increased adhesion and stress transfer between phases. However, increasing the amount of flour leads to a decrease in impact resistance and greater brittleness of the composite. Adding up to 3% by weight of nano calcium carbonate also improved the mechanical properties, but similar to flour, the impact resistance decreased. Overall, the appropriate selection of the type and number of additives can help improve the performance of nanocomposites, but it is also essential to pay attention to negative effects such as reduced impact resistance.
Mechanical conversion of wood and wooden fittings
Fardad Golbabaei; Reza Hajihassani; Kamyar Salehi
Abstract
With full respect for the principles of linking wood and conservation project Eldar pine because having good mechanical properties and availability of a wood structure in the form of pavilions chose alcove to the octagon without internal column with computer software Sketch up of Alborz research center ...
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With full respect for the principles of linking wood and conservation project Eldar pine because having good mechanical properties and availability of a wood structure in the form of pavilions chose alcove to the octagon without internal column with computer software Sketch up of Alborz research center with trees and landscaping of the complex was built. In making these structures all stages of the preparation of the wooden parts of drying are quite principled and dried in the open air during the six months were roof wood structure with the use of Eldar pine just Lambe was made in setting up the ceiling of solar connection on an octagonal timber wood using mortise and tenon mode and auxiliary metal was used. Sliding windows can be made to occupy less space. After completion of the period of three months to review the different pieces in different parts of the structure and measurements of physical densities, shrinkage and swelling and mechanical testing of hardness and impact resistance and protection review different parts of the fungal infection and decay structures was investigated. Since shortly after the beginning of the measure is going to change in the early stages of measuring statistically Darnbvdh but in the last stage of a decrease in density of about 5% and reduce the hardness of about 8% were signs of shrinkage and swelling in various parts of it to be seen.
Composite wood products
Hossein Rangavar; Mohammad hassan Payan
Abstract
In this study sound absorption coefficient and hardness of gypsum particleboard produced with kenaf stalk and nano clay were investigated. Variables in this study were weight ratio of kenaf stalks to poplar wood in three levels (40, 50 and 60 %) and nano clay content (0, 3 and 6%) based ...
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In this study sound absorption coefficient and hardness of gypsum particleboard produced with kenaf stalk and nano clay were investigated. Variables in this study were weight ratio of kenaf stalks to poplar wood in three levels (40, 50 and 60 %) and nano clay content (0, 3 and 6%) based on dried mass of wooden particles. Sound absorption coefficient determined according to ISO 10534-1 and hardness was measured in accordance with the ASTM D-1037 standards. The sound absorption coefficient was measured at four frequencies of 250, 500, 1000, and 2000 Hz. The obtained results showed that with increasing frequencies, sound absorption coefficient increased. With increasing ratio of kenaf stalk in boards, hardness decreased, but sound absorption increased. Furthermore, increase in percentage of nano clay used in the boards increased the hardness and reduced the sound absorption in coefficient in gypsum particleboard. Generally, the highest sound absorption coefficient was shown the boards produced with 60% kenaf and without nano clay in frequencies of 2000 Hz.
