Composite wood products
Abolfazl Kargarfard
Abstract
Abstract: The application of corn stalks in the production of oriented strand board (OSB) is investigated. Corn stalks strands were produced in three sizes of 50, 75 and 100 millimeters length and dried to reach 2% moisture content. Oriented strand boards were made using either urea formaldehyde, melamine ...
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Abstract: The application of corn stalks in the production of oriented strand board (OSB) is investigated. Corn stalks strands were produced in three sizes of 50, 75 and 100 millimeters length and dried to reach 2% moisture content. Oriented strand boards were made using either urea formaldehyde, melamine formaldehyde and phenol formaldehyde resin, and two press temperatures of 175 and 185 ° C. OSB boards using poplar wood strands, 100 millimeters long were also produced as control samples. The results of strength measurements of the boards were statistically analyzed using factorial experiment and completely randomized block design. The grouping of the averages was based on Duncan Multiple Range Test. The results showed that the effect of the resin type on the flexural properties and internal bonding of the boards is statistically significant and boards produced using phenol formaldehyde resin exhibited the lowest modulus of rupture, modulus of elasticity and internal bonding strength. However, the adhesive type did not statistically influence the physical properties. The strand length also statistically influenced the board strength properties and boards made using poplar strands showed higher strength compared to corn stalks strands. The thickness swelling of the poplar OSB was almost twice the values of corn stalks OSB but the water absorption of these boards was lower than of corn stalks OSB. Press temperature adversely affected the modulus of rupture and elasticity, but higher press temperature improved the internal bonding strength. Higher press temperature increased the physical properties of the boards.
Iraj Shiyarkar; Asghar Tabei; Arash Farajpoor Roodsari
Abstract
This study was conducted to determine and compare the morphological characteristics and chemical components of Corn stalks (Zea mays: 704 & Oilseed varieties) cultivated in Astara area. Samples were prepared from both varieties, a part of stalks were selected for chemical components determination ...
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This study was conducted to determine and compare the morphological characteristics and chemical components of Corn stalks (Zea mays: 704 & Oilseed varieties) cultivated in Astara area. Samples were prepared from both varieties, a part of stalks were selected for chemical components determination and the rest was used to examine the morphological features. The average of fiber length, fiber diameter, lumen diameter and fiber wall thickness for oilseed variety and 704 variety were measured as0.859 mm, 23.63 µm, 16.62 µm ,3.51 µm and0.727 mm, 18.77 µm, 11.39 µm and 3.7 µm respectively. The average percentage of cellulose, lignin, acetone extractives, alcohol extractives, hot water extractives and ash for oilseed variety was measured as 36.99, 20.5, 13.85, 2.02, 7.53 and 6.71, respectively. The relevant values for 704 varieties were 34.33, 17.5, 12.35, 1.35, 6.30 and 5.55 percent. Fiber dimensions and biometric coefficients between nodes and internodes, and between the varieties were compared and the results showed that there were significant differences between fiber length, fiber diameter, fiber lumen and biometric coefficients. The fiber dimensions and biometric coefficients between nodes and at the internododal sections of both varieties are compared and there was significant difference between all variables. The comparison of chemical components between stalk with and without bark for each variety showed that there were significant differences between the content of cellulose, lignin, hot water extractives and ash. However, there was no significant difference between lignin from 704 varieties. In comparison of chemical components between two varieties in stalk with bark, there were significant differences between the content of cellulose, lignin, acetone extractives, hot water extractives and ash; whereas in the case of stalk without bark, these differences were significant only for the acetone extractives, hot water extractives and ash.
