Three banana varieties, (Musa liukiuensis, Musa acuminta and Musa chilicarpa) are grown in Sri Lanka. Those varieties were examined for their suitability for pulping and paper making using different chemical methods. Their physical, morphological and chemical characteristics and fiber dimensions were examined. Pulping was carried out using Kraft process (Na2SO3), Soda-EtOH process and Modified process (NaOH + EtOH + Hexane). The modified process gave the highest yield. Pulps obtained were mixed with different quantities of used paper to manufacture paper. Quality of the paper produced was enhanced using fillers, methylated cellulose and cellulose xanthate. Properties such as Kappa number, bursting strength, thickness, alpha, beta and gamma cellulose contents were examined.
The bursting strength of commercially available 450 µm paper (2.75 Kgm-2) was achieved with paper containing 40% banana leaves. Kappa number of prepared pulp was lower than commercially available accesia ceyal and eucalyptus globules pulps, which have values around 12-14. Lower Kappa numbers indicate that the bleachability, delignification and hardness of a paper prepared by the banana pulp are higher than in a paper prepared by the commercially available pulps. Therefore, prepared pulp can be used to make high quality papers. The banana pulp prepared contained 85% (w/w), 6.51% (w/w) and 8.49% (w/w) of alpha, beta and gamma cellulose contents, respectively. The high strength shown by the paper prepared could be attributed to the high alpha cellulose content, which is responsible for the strength of the paper. Furthermore, Gamma cellulose of the pulp which has an adverse effect on the strength of the paper, could be reduced below 10%. According to the results of this study, it can be concluded that the Modified process (NaOH+EtOH+Hexane) is more suitable than the conventional methods for pulping of banana leaves.
Furthermore, banana leave pulp can be successfully used to prepare papers, which can be used for several value added applications such as writing papers, wrapping papers, wedding cards, greeting cards and souvenir boxes, etc..
Key words: Banana, fiber, pulp, paper
T. H.N.R.T. Hewage and L. Karunanayake
Department of Chemistry, University of Sri Jayewardenepura, Nugegoda, Sri Lanka