Wood Modification and Wood Preservation
mostafa maleki golandouz; ali Bayatkashkoli; Hadi Gholamiyan; Mahmoud Reza Hosseini Tabatabaei; Saeed Reza farrokhpayam
Abstract
Abstract
Background and Objective: Date palm is one of the important sources of lignocellulosic materials in Iran. The structure of date palm wood is a monocot plant and is very different from the wood of dicot trees. This raw material needed to be studied, therefore, an environmentally friendly approach ...
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Abstract
Background and Objective: Date palm is one of the important sources of lignocellulosic materials in Iran. The structure of date palm wood is a monocot plant and is very different from the wood of dicot trees. This raw material needed to be studied, therefore, an environmentally friendly approach to date palm modification and the behavior of some mechanical properties for use in the wood and furniture industry was investigated.
Materials and Methods: Four date palms were obtained from Sistan and Baluchestan province in Zabol city. The trunks were cut into four two-meter sections along the trunk for lightness and ease of transportation in the wood cutting workshop of the Faculty of Natural Resources, Zabol University. Test samples were prepared from different positions along the cross sections and at different heights inside the trunk. The aforementioned samples were prepared and prepared for mechanical testing and thermal modification. To determine the mechanical properties before modification, tests of tensile strength parallel to the vascular bundles, tensile strength perpendicular to the vascular bundles, shear strength parallel to the vascular bundles, and compressive strength parallel to the vascular bundles were performed. The test specimens were modified for heat treatment in a heat chamber (oven) at 11 different temperatures (120 to 210°C) by maintaining a constant temperature for 2 hours and the same time. The behavior of some properties including flexural strength, modulus of elasticity, roughness meter, and resistance to screws and nails were tested before and after the thermal modification operation for the suitability in the furniture industry. Analysis of variance of heat treatment was performed at different temperatures.
Results: The results showed that the average mechanical properties before modification, tensile strength tests parallel to vascular bundles, tensile strength perpendicular to vascular bundles, shear strength parallel to vascular bundles, and compressive strength parallel to vascular bundles were determined with an average of 85.07, 1.31, 3.58, and 19.79 kg/cm2, respectively. During the modification operation, light smoke and a very fragrant odor with a pleasant aroma were emitted in the laboratory. This phenomenon was one of the signs of changes in the properties of date palm after modification. Also, the behavior of some properties, including the bending strength (MOR) of unmodified and modified date palm samples, was recorded with an average of 39.109 and 70.719 kg/cm2, respectively. The highest average modulus of elasticity (MOE) was calculated to be 2356.38 and 2677.57 kg/cm2, respectively. The modification process at different temperatures showed that in the temperature range of 160 oC, an increase in MOR and an increase in MOE occurred. However, with increasing heat treatment temperature in subsequent samples, the MOR and MOE values decreased. In the 210 oC treatment, the samples had almost a superficial burn state. Also, the screw resistance test showed an increase in resistance compared to the nail after modification. The results of the roughness test after modification, in the temperature range of 150 and 160 oC, witnessed a low level of surface changes and smoothness.
Conclusion: Referring to this research, it is the beginning of entering into creating basic knowledge for thermal modification of date palm wood. Overall, it offers promising ways to tailor the properties of this lignocellulosic material to suit different applications while maintaining its renewable and environmentally friendly nature. Embracing these advances may pave the way for the development of these innovative and sustainable materials in the wood, furniture, and home interior industries in the coming years.
Composite wood products
Maryam Ghorbani; null null; farhad fooladian
Abstract
The Use of agricultural plants wastes as an alternative forest resources in the cellulose industry can be recommended due to the severe shortage of wood raw material and restriction of forest harvesting. The aim of current research was to investigate the effect of thermal modification on applied properties ...
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The Use of agricultural plants wastes as an alternative forest resources in the cellulose industry can be recommended due to the severe shortage of wood raw material and restriction of forest harvesting. The aim of current research was to investigate the effect of thermal modification on applied properties of composite made from sunflower stem flour-polypropylene. Thermal modification of sunflower stems was done at temperatures of 160, 180 and 200°C for 30 minutes and mixed with polypropylene in ratio of 30wt%. Test samples were prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. FTIR spectroscopy of sunflower stem flour confirmed the chemically changes due to thermal modification. More integration and uniform distribution, and less cavities were observed in the scanning electron micrographs of failure surface. The removal of hemicellulose of sunflower stem flour improved the thermal stability of composite, which thermal gravimetric analyzer (TGA) confirmed it with increasing in modification temperature up to 180°C. Modification at 200°C decreased thermal stability compared to other temperatures. Thermal modification leads to significant decrease in water absorption and improvement in bending and tensile properties due to hemicellulose degradation, increasing the crystallinity, loss of polarity, increased compatibility between the two phases of composite and uniform distribution of fillers in polymeric matrix. Notched impact strength of modified composites decreased due to better adhesion between lignocellulosic filler and polymer that facilitate the crack development along the interface.
Composite wood products
ghasem asadpour; seyyed majid zabihzadeh; Maryam Ghorbani; mahmoud davoudi
Abstract
Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, ...
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Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, 30 and 40%. Test samples prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. According to the results, bark flour increased water absorption, tensile and bending modulus. High proportion of bark fillers declined mechanical strength. Thermal modification significantly improved physical and mechanical properties of composite. Using lignocellulosic material flour bark hornbeam, tensile modulus and flexural modulus of composite material background had the highest improvement. In comparison between mechanical properties, impact resistance by adding flour bark had the greatest decrease. Thermal modification by increasing the crystallity, hemicellulose degradation, loss of polarity, increased compatibility between the two phases and uniform distribution of bark fillers in polymers, increased mechanical resistance.
