تأثیر ارتفاع بر مشخصات الیاف، ترکیبات شیمیایی و بازده خمیر کاغذ کرافت چوب کاج بروسیای منطقه کلاله گرگان

This study was aimed to investigate the effect of altitude on fiber characteristics, chemical composition and kraft yield pulp of Brutian pine. Wood samples were collected from different altitudes as 450, 750 and 960m of Arabdagh plantation, located in Kalaleh region in the northeast of Golestan province. Three healthy sample trees of Brutian pine were cut from each altitude. Maceration of earlywood and latewood were conducted usingFranklinmethod, then fiber characteristics (fiber length and diameter, lumen diameter and cell wall thickness) were measured, using light microscope. Tappi test methods were used to determine chemical compositions such as cellulose, lignin, ash and extractives content in wood. Kraft pulp was prepared at these condition: AA, 18 and 20 percent; time 60, 90 and 120 min. Analysis of variance of fibers characteristics and chemical composition was conducted using completely randomized design, then mean values were compared, using Duncan test. Factorial experiments were used for comparison of the pulp yields and kappa numbers. Results showed that between early wood and late wood fibers characteristics of three altitudes significant difference exists with level of 5%. Measured fiber from altitudes 750 and 960m were maximum and minimum values, respectively. Cellulose content was significantly higher in altitude 750m, while lignin and extractives content were higher in altitude 960m which showed significant difference with level of 5% by comparison. Ash content was not significantly different for three altitudes. Obtained pulp from altitude 960m, because of  lower kappa number is considered as proper pulp for production bleachable strength pulp, if suitable refining is carried out. On the other hand, obtained pulp from altitude 750m, because of suitable yield, can be used in different kinds of paper production such as linerboard and different wrapping paper.