اثر دما و زمان ماندگاری در تیمار روغن‌گرمایی بر ویژگی‌های فیزیکی و مکانیکی چوب نراد (Abies sp.)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 کارشناس ارشد علوم و صنایع چوب و کاغذ، گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، ایران

2 دانشیار گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، ایران

3 استاد گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، ایران

چکیده

در این پژوهش تأثیر دما و زمان ماندگاری در تیمار روغن‌گرمایی بر ویژگی‌های فیزیکی و مکانیکی چوب نراد بررسی شد. نمونه‌هایی به ابعاد 20×20×250 میلی‌متر (مماسی×شعاعی×طولی) از چوب نراد تهیه و در دماهای 200 و 230 درجة سانتی‌گراد و زمان‌های ماندگاری یک، سه و پنج ساعت در روغن سویا تیمار شدند. برای ارزیابی تغییر وزن و ابعاد نمونه‌ها، وزن و ابعاد آن‌ها پیش و پس از تیمار تعیین شد. سپس، نمونه‌ها به مدت دو هفته در شرایط کلیمای آزمایشگاه نگهداری شدند. خمش استاتیک، جذب آب و واکشیدگی، دانسیتة خشک، و مقاومت به ضربه (بدون فاق) بر نمونه‌های آزمون بررسی شد. نتایج نشان داد تیمار روغن‌گرمایی اثری معنادار بر دانسیتة نمونه‌ها ندارد؛ اما ابعاد و وزن نمونه‌ها به طور معناداری کاهش پیدا می‌کنند. میزان کاهش ابعاد در جهت مماسی بیشتر از جهت شعاعی بود. این نشان می‌دهد چوب در این جهت دچار فروریزش ساختاری یا کلاپس می‌شود. همچنین نتایج حاکی از کاهش میزان جذب آب و رطوبت و واکشیدگی نمونه‌ها پس از تیمار بود. آزمون خمش استاتیک نیز نشان داد تیمار روغن‌گرمایی باعث کاهش مدول الاستیسیته و مدول گسیختگی می‌شود. در آزمون مقاومت به ضربه تفاوت معناداری مشاهده نشد.

کلیدواژه‌ها

عنوان مقاله [English]

Influence of Temperature and Holding Time in Oil Heat Treatment on Physical and Mechanical Properties of Fir Wood (Abies Sp.)

نویسندگان [English]

  • Mohammad Reza Abde 1
  • Amir Mootab Saei 1
  • Behbood Mohebby 2
  • Saeed Kazemi-Najafi 3
1 Graduated M.Sc, Student, Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Tarbiat Modares University, Noor, I.R. Iran
2 Associate Professor, Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Tarbiat Modares University, Noor, I.R. Iran
3 Professor, Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Tarbiat Modares University, Noor, I.R. Iran
چکیده [English]

Influences of temperature as well as holding time on physical and mechanical properties of Fir wood were studied in this work during the oleothermal wood modification. Wood samples were cut and treated oleothermally in the soybean oil at 200 and 230°C for the holding time of 1, 3 and 5 hours. Weights and the dimensions were measured before and after treatment. Bending strengths, water absorption and swelling, dry density and the impact load resistance (un-notched) were determined in the samples. Results revealed that the oleothermal treatment of wood had no significant effects on the density. Dimensions and the weights were reduced significantly in the treated wood. There was more reduction in the radial dimension than that of the tangential one. It means that wood was collapsed in this direction after treatment. Reductions in the water and moisture absorption as well as the swelling were determined in the samples. Bending tests revealed reduction in moduli of the elasticity and the rupture. There was no significant change in the impact load resistance of the treated samples.

کلیدواژه‌ها [English]

  • Oleothermal Wood Modification
  • Fir wood
  • Physical properties
  • Mechanical properties

مراجع

 
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