W M Kpikpi and I Sackey
Keywords: Gliricidia sepium, Gmelina arborea, pulp, paper.
Abstract: The anatomy of the wood of Gliricidia sepium has been studied for suitability as pulpwood. Dimensions of the wood fibre were measured microscopically to determine Runkel ratio and the Flexibility coefficient. The fibre morphology ratios inform preliminary decisions on the suitability of the species as pulpwood. Slides of microtome sections were made of the wood for microscopic study of the cell and tissue types and their relative proportions that constitute the wood. Low Runkel and high Flexibility ratios and a preponderance of fibres relative to other cells are desirable and would normally encourage the pulping and paper-making trials. The wood was pulped and hand-made paper sheets were tested for physical strength properties. The studies were duplicated for Gmelina arborea, which is already in use as pulp and paper-making hardwood, for comparison. Gliricidia sepium has Runkel ratio of 1.22 and coefficient of flexibility of 0.45 compared with Gmelina’s 0.19 and 0.88 respectively. The relative fibre volume for Gliricidia is 58.9% and about 41% other cells combined, while Gmelina has 72% fibres and 28% all other cells together. Pulp yields in Gliricidia and Gmelina are 46.5% and 49.2% respectively, while both species showed some good physical properties in the paper sheets: Gliricidia produced Burst property of 3.75kg cm-2 and Tear of 155g at pulp freeness of 510 SR, while Gmelina recorded 3.98kgcm-2 and Tear of 165g at freeness 360 SR. These values of physical strength properties combined with the reported features of the wood anatomy and the vegetative growth characteristics reported from the literature support the conclusion that Gliricidia sepium has great potential as a good pulpwood.
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