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Pulping characteristics of Pinus caribaea grown in Sri Lanka

Pulping characteristics of Pinus caribaea grown in Sri Lanka

Palmer, E. R. and Ganguli, S. (1982) Pulping characteristics of Pinus caribaea grown in Sri Lanka. Tropical Products Insittute (TPI), London, UK. ISBN 0859541509

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Three samples of Pinus caribaea grown in Sri Lanka were examined. One sample, aged nine years, was grown on an evergreen forest site; the other two, aged 20 and 22 years, were grown on a Montane forest site. The average density of the wood of the three samples was: 548 kg per cubic metre (9-year old), 476 kg per cubic metre (20-year old) and 377 kg per cubic metre (22-year old). The youngest sample had the highest cellulose and the lowest lignin contents. Sulphate pu lps were obtained from all samples without difficulty with an unbleached screened yield of 45-47% at kappa numbers around 40. The youngest sample yielded pulps with the highest tearing strengths and the lowest tensile and bursting strengths. There was insufficient information to reach a firm conclusion of the reasons for these unexpected findings, but it is suggested that the difference in growing conditions caused differences in wood quality so great that the expected progression of density, chemical composition and pulp properties with age were disguised. All pulps with a kappa number less than 30 were bleached using a chlorination, alkaliextraction, sodium hypochlorite, chlorine dioxide sequence. Bleached pulps with ISO-brightness of 82.5-84 were obtained in yields of 40-43%. The most satisfactory results were obtained from the bleaching of pulps with a kappa number between 25 and 30. If the P. caribaea samples were pulped as a mixture, they would most likely yield a pulp with properties similar to those of pulps from Douglas Fir and Southern Pines, and most useful for sack and packaging grades of paper. They could be useful also, especially those from the Kottawa site, if mixed with straw pulps to increase strength characteristics.

Item Type: Book
Additional Information: © Crown copyright 1982. Note on publisher affiliation: Tropical Products Institute (TPI) is a predecessor of the Natural Resources Institute (NRI). The NRI has been a specialist research and teaching institution of the University of Greenwich since 1996.
Uncontrolled Keywords: pulp, characteristics, Pinus caribaea, Sri Lanka, density, pine
Faculty / School / Research Centre / Research Group: Faculty of Engineering & Science > Natural Resources Institute
Faculty of Engineering & Science > Natural Resources Institute > Agriculture, Health & Environment Department
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Last Modified: 06 Dec 2019 16:22

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