Document Type : Research Paper

Authors

• Mostafa Maleki golandouz ¹
• ali Bayatkashkoli ²
• Hadi Gholamiyan ³
• Mahmoud Reza Hosseini Tabatabaei ⁴
• Saeed Reza farrokhpayam ⁵

¹ Ph. D Wood and Paper Science and Technology Group, Faculty of Natural Resources, University of Zabol, Zabol, I.R. Iran

² Prof Wood and Paper Science and Technology Group, Faculty of Natural Resources, University of Zabol, Zabol, I.R. Iran.

³ Associate Professor, Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Tehran, Iran

⁴ Associate Professor, Department of Civil Engineering, Faculty of Technology and Engineering, University of Zabol, Zabol, Iran

⁵ Associate Professor, Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Zabol, Zabol, Iran

Abstract

Background and Objective: Date palm is one of the important sources of lignocellulosic materials in southern region of Iran. The structure of date palm wood is a monocot yledonous plant and is very different from the wood of dicot yledonous trees. ،Therefore, an environmentally friendly approach to date palm wood modification and the behavior of some mechanical properties for use in the wood and furniture industry was investigated.
Materials and Methods: Four date palms branches were collected from Zabol city, Sistan and Baluchestan province. The trunks were cut into four two-meter sections along the length 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 of the trunk. The aforementioned samples were 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. The 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 wood 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: . This research, can be 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.

Keywords

• thermal modification
• date palm texture
• mechanical properties

Main Subjects

• Wood Modification and Wood Preservation