The Comparison of Kraft Pulp Properties from Stem and Branchwood of Hornbeam

The utilization of tree branches as potential resource of fibers، that can be supply raw materials for pulp and paper industries، additionally، increases the productivity of tree. This research was done in order to compare pulp and paper properties from branch wood and stem wood and feasibility utilization that in pulp and paper industries. Stem and branch wood samples of hornbeam with mean diameter about 15 cm were obtained from Shastkolateh educational forest (Gorgan). The measurement of fibers was done with using Franklin method and light microscopic and chemical compositions were determined according to TAPPI test methods. The Kraft pulps from stem and branch wood were prepared under constant condition include sulfudity 20%، Max temp 170˚C and Liquor to wood ratio 5/1 and variable condition include active alkali 14%، 16% and 18%، and cooking time of 90، 120 and 150 min. Ultimately mechanical properties of Handsheet were measured according TAPPI test method The statistical analysis of results indicated that independent effects of wood، active alkali، and time were significant on pulp yield and Kappa number. Comparing the pulp yield and Kappa number means were showing that yield of stem wood pulp is higher than branch wood and its kappa number is less. Analysis mechanical properties on stem and branch wood Hand sheets showed that mechanical properties of Hand sheet from stem wood are higher than branch wood. There is none meaningful difference between the most mechanical properties hand sheets of stem and branch wood، that produced under cooking condition include sulfudity 20%، active alkali 18% and cooking time 150 min. therefore this condition would suggest for simultaneous cooking branch and stem wood