influence of temperature and holding time in oil heat treatment on physical and mechanical properties of fir wood (abies sp.)

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.