influences of combined-hydro-thermo-mechanical (chtm) modification on moisture absorption and dimensional stability of poplar wood

نویسندگان

پیمان فلاح مقدم-بهمبری

دانش آموختۀ کارشناسی ارشد علوم و صنایع چوب و کاغذ, دانشگاه تربیت مدرس، نور، ایران بهبود محبی

دانشیار، گروه علوم چوب و کاغذ دانشگاه تربیت مدرس، نور، ایران حوری شریف نیا دیزبنی

دانشجوی دکتری فراورده های چندسازۀ چوب، دانشگاه تربیت مدرس، نور، ایران

چکیده

in this research work, it was planned to study influences of hydrothermal treatment temperature, holding time and press temperature on wood density, spring back, moisture absorption as well as dimensional stability of combined-hydro-thermo-mechanically modified poplar wood. wood blocks were treated hydrothermally at temperatures 120, 150 and 180°c for holding time of 0, 30 and 90 min. afterwards, those blocks were compressed immediately in a press at temperatures 160 and 180°c for 20 min with a compression set of 60% in radial direction. density, spring back, moisture absorption and dimensional stability of treated samples were determined and compared with the untreated ones. results revealed that density was increased due to the treatment. spring back was reduced by raise of hydrothermal treatment temperature. moisture absorption was also decreased by treatment temperature. although, any increase of relative humidity caused increase of moisture content in compressed wood, however it was less than that of untreated one. any extended holding time had no significant effects on moisture absorption. there was also a reductive effect of press temperature on moisture contents. radial swelling of treated samples was also reduced by gained treatment temperature. press temperature also decreased the swelling; however, it was not as much as the treatment temperature. generally, this research work indicated proper capability of this innovated combined-hydro-thermo-mechanical wood modification on properties of compressed wood to be used practically.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

بررسی اثر تیمار روغن گرمایی بر ویژگیهای فیزیکی و مکانیکی چوب نراد(abies sp.)

in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...

15 صفحه اول

water absorption and dimensional stability of polypropylene/acetylated wood fiber

influences of the wood fiber acetylation as well as the compatibilizer mapp on water absorption, thickness swelling and dimensional stability of acetylated wood/ polypropylene composites (wpcs) were the main concerns of this research. wood fibers were acetylated with acetic anhydride without using any catalyst to achieve weight percent gains (wpgs) of 4.5, 7.5 and 17.6%. the acetylated fibers w...

متن کامل

modification of nanoclay for improving the physico-mechanical properties of dental adhesives

هدف اصلی این مطالعه تهیه یک سامانه نوین چسب عاجی دندانی بر پایه نانورس پیوند شده با پلی متاکریلیک اسید، نانورس پیوند شده با پلی اکریلیک اسید، مخلوط نانوسیلیکا و نانورس پیوند شده با پلی متاکریلیک اسید، مخلوط نانوسیلیکا و نانورس پیوند شده با پلی اکریلیک اسید و نانورس پیوند شده با کیتوسان اصلاح شده با گلایسیدیل متاکریلات است. پیوند پلی متاکریلیک اسید و پلی اکریلیک اسید بر ری سطح نانورس در حضور و ...

Stability Analysis of Salt Cavern Gas Storage Using 2D Thermo-Hydro-Mechanical Finite-Element Software

Ensuring the stability and integrity of underground gas storage salt caverns is a very complicated subject due to the non-linear and time-dependent behavior of rock salts under complicated thermal and mechanical loading conditions. For this reason, pressure and temperature fluctuations in the caverns and their surrounding strata must be integrated into the analysis and the numerical tools that ...

متن کامل

Thermo-hydro-mechanical Coupling in Clay Barriers

A complete thermo-hydro-mechanical model is presented to tackle the complex coupling problems encountered in clay barriers. A detailed formulation coupling the heat, moisture (liquid water and water vapour) and, air transfer in a deformable unsaturated soil is given. The formulation of the AlonsoGens’s mechanical model for unsaturated soil is also incorporated. The sensitivity to some parameter...

متن کامل

Three Dimensional Analyses of Combined Gas, Heat and Nuclide Transport in a Repository Considering Thermo-Hydro-Geo- Mechanical Processes

To study the coupled thermo-hydrologic-geomechanical processes and their influence on gas and nuclide transport in a two phase flow through the porous medium, a coupling of the thermo-hydrodynamic code TOUGH2 and the thermo-mechanic code FLAC3D is described and applied to analyze three dimensional gas, heat and nuclide transport in a repository for disposal of heat generating nuclear waste in a...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید


عنوان ژورنال:
جنگل و فرآورده های چوب

جلد ۶۸، شماره ۱، صفحات ۱۸۱-۱۹۳

کلمات کلیدی
in this research work it was planned to study influences of hydrothermal treatment temperature holding time and press temperature on wood density spring back moisture absorption as well as dimensional stability of combined hydro thermo mechanically modified poplar wood. wood blocks were treated hydrothermally at temperatures 120 150 and 180°c for holding time of 0 30 and 90 min. afterwards those blocks were compressed immediately in a press at temperatures 160 and 180°c for 20 min with a compression set of 60% in radial direction. density spring back moisture absorption and dimensional stability of treated samples were determined and compared with the untreated ones. results revealed that density was increased due to the treatment. spring back was reduced by raise of hydrothermal treatment temperature. moisture absorption was also decreased by treatment temperature. although any increase of relative humidity caused increase of moisture content in compressed wood however it was less than that of untreated one. any extended holding time had no significant effects on moisture absorption. there was also a reductive effect of press temperature on moisture contents. radial swelling of treated samples was also reduced by gained treatment temperature. press temperature also decreased the swelling; however it was not as much as the treatment temperature. generally this research work indicated proper capability of this innovated combined hydro thermo mechanical wood modification on properties of compressed wood to be used practically.

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023