الفهرس 
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Abstract
In Egypt pulp and paper industry facing difficult situation, because they depend only on bagasse and waste paper in spite a large amount of agricultural residues have not been utilized. Also a large amount of imported wood pulp is blended with local pulp (bagasse) to improve the strength properties of paper.
In this work two agricultural materials namely: banana stem and corn stalk were used to fill the above gaps. The first one (banana stem) was chosen due to its long fiber length for writing and printing paper. The second one ( corn stalk ) was chosen to produce newsprint, due to its short fiber and high ash, such properties increase opacity which is of prime importance for newsprint.
This study deals with optimizing pulping conditions of the banana stem to substitute softwood pulp in writing and printing paper. Scanning micrograph and chemical composition of banana stem indicate that banana fibers are flat, flexible, long (2.24 mm) and the raw banana is characterized with high cellulose (65%) and low lignin (13.5%) contents. The banana stem was pulped using Kraft process (8.5 % alkali as Na2O and 17% sulfidity cooked at 105oC for 3 hr. The obtained pulps were characterized with respect to yield (64%) and Kappa number (35%). Compared to imported softwood pulp, all strength properties and opacity are high. This is attributed to the long banana fibers and the high cellulose content. High quality of writing and printing paper was obtained by a furnish blend ratio of 20%-80%, banana stem pulp, and commercial bagasse pulp respectively.
The chemical composition of corn stalk as well as fiber morphology, fiber length and diameter were carried out. Furthermore, Kraft pulping process using different cooking conditions (temperature, 125 – 170ºC, time, 15 - 40 min., and % alkali 9 - 12%) were done at laboratory scale. The obtained pulps were characterized with respect to %yield, %rejects, kappa number and rest alkali.
The mechanical properties of hand sheet paper were explained in details, according to different cooking conditions. The high ash content, the relatively short fiber and the fiber morphology of corn stalk can attribute to positive effect with respect to bulk, opacity and the necessary strength of paper which are important properties in newspaper.
Industrial trials were carried out using Pandia continuous digester (74 tons corn stalk kraft pulp was produced) and ninety tons newsprint paper (furnish: 86.5% bleached corn stalk pulp + 13.5 bleached soft wood pulp) was obtained using Furdirinier paper machine. The produced newsprint was printed and commercialized by four famous newsprint companies in Cairo – Egypt (about twenty tons for each).
Comparison with the imported newsprint paper indicated that, the produced newsprint has better qualities with respect to opacity, and strength properties. Findings from industrial and commercialized trials in this study provide insights into new opportunities to utilize corn stalk pulp as better alternative to produce good quality of newsprint.