This study has been conducted to investigate the infl uence of temperature levels in the densifi cation process by hot-press methods on the physical and mechanical properties of false walnut wood (Pterocarya fraxinifolia). For this purpose, wood specimens from fi ve standing trees were compressed at different densifi cation temperatures (110, 140 and 170 °C). Then, the data of oven dry density, modulus of rupture, modulus of elasticity in bending and withdrawal strength of nail of compressed wood were analyzed by SPSS software. Analysis of variance (ANOVA) indicated that the densifi cation temperature had signifi cant effects on the physical and mechanical properties. The most suitable temperature level was 140 °C for a higher density, modulus of rupture, modulus of elasticity in bending, and withdrawal strength of nail in the densifi cation of false walnut wood. Increase of 27 % in the density, 80 % in the modulus of elasticity (MOE), 252 % in the modulus of rupture (MOR) and 215 % in the withdrawal strength of nail were obtained after densifi cation.

This study aimed to scrutinize chemical treatment of Mazandaran Wood and Paper mill activated sludge with 3 % acetic acid for the manufacture of environmentally eco-friendly bio composite. In this study, the paper pulp required was obtained from the waste newsprint paper. The activated sludge was treated in a beaker for 3 min in 3 % acetic acid and then in a water bath at 75 and 100 °C for 45 and 90 min. After that, the treated activated sludge was mixed and refi ned with waste newsprint paper pulp at ratios of 0, 5, 10, 15 and 20 %. The test specimens were prepared according to TAPPI standard and the physical properties (water absorption and porosity) and mechanical (tensile strength, tear strength, ring crush test, burst strength and folding strength) were measured. The results showed that the activated sludge treatment caused the increase in tear strength, ring crush test, burst strength and porosity as well as the decrease in water absorption, tensile strength and folding strength. FT-IR spectrum of the treated samples showed that the treatment with acetic acid strengthened and activated the functional groups on the surface of activated sludge fi bers. The activated sludge added at a level of 5 % at 100 °C for 90 min as well as at a level of 20 % at 75 °C for 45 min was more suitable than other treatments.