Iranian Journal of Wood and Paper Science Research
Year:2000 | Volume:- | Issue:9|Papers Count:3

In this investigation some anatomical, chemical and pulping suitability of two Iranian hardwood species which predominate in the Caspian forests were examined. The species are carpinus betulus (Hornbeam) and parotia persica (Ironwood).The results of this study revealed that:The average fiber length of carpinus betulus is 1.4 mm., fiber diameter 18 mm, and cell wall thickness 3.37 mm, while inparotia persica, fiber length, cell diameter and cell wall thickness are 1.34 mm, 17.3 mm and 3.48 mm respectively.The overall average of cellulose content: of carpinus betulus and Parotia persica were measured at 48.5, and 46.1 percent, and the lignin content at 17.5 and 21.5 percent respectively.The wood of each of the above species was cooked by means of a kraft process without difficulty but, there was a slight decrease in yield and kappa number with increase active alkali.The pulping yield with active alkali of14% was about 49.6 and with 20% was 43.44 percent, while the pulping yield of parotia persica in active alkali of 14% was 43.04 and in 20% about 37.79 percent. Thus, it may be concluded that for production of wrapping paper from carpinus betulus and parotia percica, using active alkali of 14% might give better quality paper and for production of printing paper from these two species active alkali of 20 percent might be desirable.

In this investigation Eucalyptus camaldulensis wood for particle -board production and determinating physical and mechanical properties of boards have been studied. Variable factors such as resin content in three levels (9, 10 and 11 percent) and press time in three levels (5, 6 and 7 minutes) were investigated.Other factors such as resin type, hardner type, closing press time, mat moisture, board density and etc. were assumed constant. Three boards were produced for each combination of variables. Based on the DIN-68763 standard physical and mechanical properties including Modulus of Rupture (MGR), Modulus of Elastisity (MOE), Internal Bonding (IB) and thickness swelling (TS2 and TS24) after 2 and 24 hours immersion in water were tested.Based on the factorial experimental design at completely random block test data was analysis. The rcsuHs showed that polymerization of resin could be better at the amount of 11 percent resin content and 7 minutes of press time for partideboard production from Eucalyptus camaldulensis wood.

To determine major engineering properties of Hornbeam wood (Carpinus betulus L.) in Vaisar region of Caspian Forests (North of Iran), adopting ASTM (D-143) Standard specifications, the matched small clear specimens were prepared. The test materials were derived from three randomly chosen trees. Mechanical and physical properties were measured on two moisture states: green and air - dried (at 12% moisture content).The influence of locations of specimens in the height of tree trunks and geographical directions were tested on target properties. From the results of this study it could be concluded that, there were no significant differences between the various heights and geographical directions from the pith for most of the properties investigated.Toughness was not influenced by moisture content. The average value of hardness of Hornbeam wood in transverse sections were the same as side_grain sections in green condition, but air-drying caused increasing the value of cross - sections about 30% The compression strength perpendicular r to the grain showed differences in wet and dry conditions.