Sorghum bicolor, A New And Valuable Capability of Nonwood lignocellulosic Materials for Pulp and Paper Industry

In this study, physical, chemical, and papermaking properties of sweep plant stalk (sorghum bicolor) prepared from northern and northwestern areas of Iran was studied to evaluate its papermaking potential. The prepared stalks were cut into three parts in length and then the bark and core of each sample were seperated. Morphological characteristics, papermaking factors, and chemical composition including amount of lignin, cellulose, extractives and ash of each sample were determined according to TAPPI standards. The results of papermaking factors of this plant’s stalk fibers (that are related to fiber length and wall thickness) indicated that it had potential of producing paper with higher strength properties compared to common raw materials and even local hardwoods. So, interesting results of chemical analysis of this plant’s stalk samples showed higher value of cellulose and lower amount of lignin in comparison with woody and nonwoody plants that is considered as one of the most important affirmative factors (easy and cheap lignin removal process) in papermaking raw materials. Results of all physical and chemical assessments showed better characteristics of the bark comparing to the core. Of course, considering the low ratio of core to bark (contrary to other nonwoody plants) it is concluded that pulp produced from whole stalk have no significant differences with pulp prepared from bark. Sweep plant of northern Iran has longer fiber with more cellulose content and less extractives in comparison with northwestern type. Thus, it is suggested to mill owners to be used as a suitable raw material in this industry.