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Title
Assessment of five successful poplar clones for kraft pulp production considering technical and economic aspects
Authors
S. MAHDAVI H. KERMANIAN O. RAMEZANI and S. MOLAVI
Received
June 27, 2012
Published
Volume 47 Issue 3-4 March-April
Keywords
growth rate, kraft pulp, screen yield, paper properties, poplar clone, ranking method, Expert Choice
Abstract
Five successful non-indigenous clones, selected based on local adaptability from a total of fifteen, were studied for their
kraft pulp production and a new ranking method based on technical and economic parameters was used to facilitate
decision making in future plantation policies. Three logs were cut at the breast height of each clone with the age of 12
years. The best screen yield mean of five clones (52.58%) was achieved applying the cooking treatment combination of
170 °C, 45 min, 18% A.A., and 23% sulfidity. Physical and mechanical properties of the handsheets prepared from the
pulp, namely average sheet apparent density, tear and burst indices and breaking length, were measured as 0.75 g cm-3,
10.67 mN m2 g-1, 5.20 kPa m2 g-1, and 7.60 km, respectively. A pair-wise comparison with nine objectives was carried
out using Expert Choice software by two unweighted and weighted (technical and economic weighting) methods. The
two ranking methods indicated that Costanzo and Triplo (clones of P. euroamericana) are the superior and,
respectively, the inferior of the clones under study, considering the objectives of the hierarchy. The other clones were
ordered differently, according to the priority of each of the methods. Despite the highest annual growth rate, sheet
density and tear index, Vernirobensis (clone of P. euroamericana) was situated second in the ranking. The results
indicated that the pulp strengths of all selected clones were higher than the strength requirement for kraft liner,
according to ISIRI 3054 standard.
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