Influence of hydrothermal treatment on the dimensional stability of beech wood

Hydrothermal treatment of wood material products with many interesting properties such as enhanced dimensional stability, lower equilibrium moisture content and increased biological durability. The effects of hydrothermal treatment on dimensional stability, oven dry density and water absorption of beech wood (Fagus Orientalis) naturally grown, has been studied in present research that extremely used in Iran. Hydrothermal applied to the wood samples (2.5Cm?2.5Cm?2.5Cm) in three different temperatures (150 oC, 160 oC, 170 oC) and four different durations (1h, 3h, 5h and 7h) in reactor. Then, the samples and their controls were immersed in water at 25 oC, 65% relative humidity for various periods. Volumetric swelling percentage and rate of the water absorption values of the samples and their controls were measured at a period of 24 hour in 8 steps on basis of oven dried dimension. The obtained data were analyzed using Microsoft Office (EXCEL 2003). The data analysis indicated that best anti-swelling efficiency value was achieved at 170 oC (treating temperature) within 1 hour (treating time) and 8 steps of soaking - dried measurement by hydrothermal treatment. Consequences for anti-swelling efficiency, decreasing of samples specific gravity, water absorption and water repellency effectiveness values obtained 27.95%, 8.49%, 56.41% and 20.20% respectively. Therefore, hydrothermal treatment showed a little decreasing at 150 oC to 170oC in specific gravity of treatment samples because maximum lessening of specific gravity obtained 8.02% in the highest condition of treatmentDimensional stability after final soaking

COMPARATIVE STUDY OF PULP AND PAPER PROPERTIES OF CANOLA STALKS PREPARED BY USING DIMETHYL FORMAMIDE OR DIETHYLENE GLYCOL

Comparision between pulping of canola stalks with dimethyl formamide and diethylene glycol was studied in order to investigate the effects of cooking temperature (190˚C, 210˚C, and 230˚C), cooking time (120 min, 150 min, and 180 min) and dimethyl formamide or diethylene glycol (50%, 60%, and 70%) on the properties of pulp and paper. SCAN viscosity was applied to estimate the extent of cellulose degradation. Responses of pulp and handsheet properties to the process were analyzed using statistical software (MINITAB 15). The results showed that DMF pulp of canola was better than DEG pulp of Canola under the same conditions of cooking and organosolv ratio. In DMF pulping and DEG pulping, cooking temperature is a significant factor affecting paper properties. Analysis of results revealed that DMF pulp canola obtained at 230 °C, 180 min, and 70% DMF had a low kappa number (25) , indicating that the desired properties of the final product dictated the optimized pulping conditions