| تعداد نشریات | 287 |
| تعداد نشریات سازمان | 85 |
| تعداد شمارهها | 3,159 |
| تعداد مقالات | 35,108 |
| تعداد مشاهده مقاله | 50,528,278 |
| تعداد دریافت فایل اصل مقاله | 90,477,391 |
ارزیابی ویژگیهای فیزیکی و مکانیکی چوب اصلاح شده با فرآیند بخارگرمایی | ||
| تحقیقات علوم چوب و کاغذ ایران | ||
| مقاله 1، دوره 32، شماره 1 - شماره پیاپی 58، اردیبهشت 1396، صفحه 1-12 اصل مقاله (313.86 K) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22092/ijwpr.2017.107597 | ||
| نویسندگان | ||
| رضا حاجی حسنی1؛ بهبود محبی* 2؛ سعید کاظمی نجفی3؛ پرویز ناوی4 | ||
| 1دانشجوی دکترا، گروه علوم و صنایع چوب و کاغذ، دانشکده منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس | ||
| 2معاونت آموزشی دانشکده منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس | ||
| 3استاد و مدیر گروه علوم چوب و کاغذ دانشکده منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس | ||
| 4استاد، گروه معماری، مهندسی چوب و سازه چوبی دانشگاه برن، سوئیس | ||
| چکیده | ||
| چکیده این پژوهش با هدف بررسی تاثیر اصلاح بخارگرمایی(Hygro-Thermal Treatment) چوب صنوبر(Populus deltoides) بر ویژگیهای فیزیکی و مکانیکی آن انجام گرفت. در این بررسی تیمار بخارگرمایی در دماهای 130، 150 و 170 درجه سانتیگراد و برای مدت زمان ماندگاری صفر، 20 و 40 دقیقه انجام شد. آزمونهای فیزیکی؛ شامل اندازهگیری افت وزن و کلاپس ناشی از تیمار، تغییرات دانسیته، ثبات ابعادی، زبری سطح و آزمونهای مکانیکی؛ شامل مقاومت خمشی و مدول الاستیسیته در چوب تیمار شده انجام شدند. نتایج نشان دادند که تیمار بخارگرمایی موجب بهبود ثبات ابعادی، افزایش کلاپس و زبری سطح و کاهش جرم و دانسیته چوب صنوبر شده است. هم چنین این فرآیند سبب کاهش مقاومت خمشی و افزایش مدول الاستیسیته گردید. از سوی دیگر، با افزایش دمای تیمار و مدت زمان ماندگاری افت وزن، افت دانسیته و هم چنین افزایش پدیده کلاپس روی میدهد؛ در حالی، افزایش ثبات ابعاد با دمای تیمار و مدت زمان ماندگاری رابطه مستقیم دارد. | ||
| کلیدواژهها | ||
| اصلاح بخارگرمایی؛ زمان ماندگاری؛ صنوبر(Populus deltoides)؛ ویژگیهای فیزیکی و مکانیکی | ||
| عنوان مقاله [English] | ||
| Evaluation of Physical and Mechanical Properties of Hygro-thermal Modified Wood | ||
| نویسندگان [English] | ||
| Reza Hajihassani1؛ Behbood Mohebi2؛ Saeid Kazemi Najafi3؛ Parviz Navi4 | ||
| 1Ph.D Student, Department of Wood and Paper Sciences, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran | ||
| 2Associate Prof., Department of Wood and Paper Sciences, Faculty of Natural Resources, Tarbiat Modares University, P.O. Box 46414-356, Noor, Iran | ||
| 3Prof., Department of Wood and Paper Sciences, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran | ||
| 4Prof., Department Of Architecture, Wood and Civil Engineering, Bern University of Applied Sciences, Bern, Switzerland | ||
| چکیده [English] | ||
| Abstract The present research work has investigated the physical and mechanical properties of hygro-thermally modified poplar (Populus deltoides) wood. The poplar wood blocks were treated hygrothermally at temperatures of 130, 150 and 170°C and for 20, 40 minutes as holding time. The physical and mechanical properties were determined for both treated and untreated wood. The properties; mass loss, collapse, specific gravity changes, dimensional stability, surface roughness, bending strength and modulus of elasticity, were determined prior to and after the treatment in all wood blocks. As expected, the hygrothermal treatment significantly improved the dimensional stability of the samples. It was also found that the hygrothermal treatment could increase collapse, surface roughness and modulus of elasticity due to the treatment. However, there were decreases in wood mass, specific gravity and bending strength of the treated poplar wood. It was revealed that the mass loss, decrease in the density as well as collapse in woos is correlated with treatment temperature as well as the holding time. While, raise of the treatment temperature as the holding time caused increase of the dimensional stability. | ||
| کلیدواژهها [English] | ||
| Hygro-Thermal Modification, Holding Time, Poplar (Populus deltoides), PHYSICAL AND MECHANICAL PROPERTIES | ||
| مراجع | ||
|
-Alvira, P., Tomás-Pejó, E., Ballesteros, M., and Negro, M.J., 2010. Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: a Review, Bioresour. Technol, 101: 4851–4861.
-Assor, C., Placet, V., Chabbert, B., Habrant, A., Lapierre, C., Pollet, B., and Perre, P., 2009. Concomitant changes in viscoelasticity properties and amorphous polymers during the hydrothermal treatment of hardwood and softwood. J. Agric. Food. Chem, 57: 6830–6837.
-Biswas, A.K., Yang, W., and Blasiak, W., 2011. Steam pretreatment of salix to upgrade biomass fuel for wood pellet production. Fuel Process Technol, 92: 1711–1717.
-Dioufa, P.N., Stevanovicb, T., Cloutierb, A., Fangb, C.H., Blanchetc, P., Koubaad, A., and Mariottib, N., 2011. Effects of thermo-hygro-mechanical densification on the surface characteristics of trembling aspen and hybrid poplar wood veneers, Applied Surface Science, 257: 3558–3564.
-Esteves, B., Marques, A.V., Domingos, I., and Pereira, H., 2007. Influence of steam on the properties of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) wood. Wood Sci. Technol, 41: 193–207.
-Garrote, G., Domínguez, H., and Parajó, J.C., 1999. Hydrothermal processing of lignocellulosic materials. Holz Roh Werkst, 57: 191–202.
-Hakkou, M., Pétrissans, M., Zoulalian, A., and Gérardin, P., 2005. Investigation of wood wettability changes during heat treatment on the basis of chemical analysis. Polymer Degradation and Stability, 89: 1-5.
-Hill, C.A.S., 2006. Wood Modification: Chemical, Thermal and Other Processes, John Wiley & Sons Ltd, Chichester, UK,p. 260.
-Jennings, J.D., Zink-Sharp, A., Frazier, C.E., and Kamke, F.A., 2006. Properties of compression densified wood, Part II, Surface Energy, J. Adhes. Sci. Technol, 20 (4): 335–344.
-Lam, P.S., Lam, P.Y., Sokhansanj, Sh., Bi, X.T., and Lim, C.J., 2013. Mechanical and compositional characteristics of steam-treated douglas fir (Pseudotsuga menziesii L.) during pelletization.Biomass and Bioenergy, 56: 116-126.
-Liu, S., 2008. A kinetic model on autocatalytic reactions in woody biomass hydrolysis. J. Biobased Mater. Bio, 2: 135–147.
-Metsa-Kortelainen, S., Antikainen, T., and Viitaniemi, P., 2006. The water absorption of sapwood and heartwood of scots pine and norway spruce heat-treated at 170◦C, 190◦C, 210◦C and 230◦C. Holz RohWerkst, 64(3): 192–197.
-Mirzaei, Gh., Mohebby, B., and Tabarsa, T., 2012. Collapsibility and Wettability of Hydrothermally Treated Wood. Iranian Journal of Wood and Paper Industries, Vol. 3, No. 1.
-Mirzaei, Gh., Mohebby, B., and Tasooji, M., 2012. The effect of hydrothermal treatment on bond shear strength of beech wood. Eur. J. Wood Prod, 70: 705-709.
-Mohebby, B., Sharifnia-Dizboni, H., and Kazemi-Najafi, S., 2009. Combined hydro-thermo-mechanical modification (CHTM) as an innovation in mechanical wood modification. In: Proceeding of 4th European Conference on Wood Modification (ECWM4). 27-29th April, Stockholm, Sweden, pp. 353-360.
-Navi, P., and Sandberg, D., 2011. Thermo-hydro-mechanical processing of wood, Engineering Sciences, Taylor & Francis Group, LLC, Swiss, p. 360.
-Popescu, C.M., and Popescu, M.C., 2013. A near infrared spectroscopic study of the structural modifications of lime (Tilia cordata Mill.) wood during hydro-thermal treatment. Spectrochimica Acta. Part A: Molecular and Biomolecular Spectroscopy, 115: 227–233.
-Ramos, L.P., 2003. The chemistry involved in the steam pretreatment of lignocellulosic materials. Quim Nova, 26: 863–871.
-Standard methods of testing small clear specimens of timber, American Society for Testing of Materials, ASTM D 143-09, 2014.
-Surface Texture: Profile method rules and procedures forthe assessment of surface texture, 1:1158-1159, ISO/DIS 4287.1. 1998.
-Thybring, E.E., 2013. The decay resistance of modified wood influenced by moisture exclusion and swelling reduction. International Biodeterioration & Biodegradation,82: 87-95.
-Xu, X., and Tang, Z., 2012. Vertical Compression Rate Profile and Dimensional Stability of Surface-Densified Plantation Poplar Wood. Lignocellulose, 1 (1): 45-54.
| ||
|
آمار تعداد مشاهده مقاله: 1,244 تعداد دریافت فایل اصل مقاله: 872 |
||