DefinePK

Abstract

ABSTRACT The physical, anatomical and chemical properties of chir pine wood were described in the first part. The pulping studies on wood samples of this species on laboratory scale are presented in this article. Trial cooks were made to determine the most suitable kraft (sulphate) pulping conditions for producing bleachable pulp with Kappa number of about 25 from 15 chir pine trees of three age groups. In laboratory tests trees of 36 - 45 years age gave maximum pulp yield. However, hand sheets prepared from the pulp of 26 - 35 years-old trees had higher breaking length and burst strength and lower tear strength than those of 36 - 45 years and higher age groups. The bleach response of pulps made from the three groups was almost identical and pulps of about 850GE brightness were obtained after a four stage (CEH1 H2) bleaching sequence. The presence of resin in chir pine wood did not constitute any special problem during its pulping. The values of tall oil were found to be about 1% and 20 - 22kg on oven-dry wood and per ton of oven-dry pulp basis respectively.