Studies on Ipomea carnea and Cannabis sativa as an alternative pulp blend for softwood:: An optimization of kraft delignification process

Ipomea cornea Jacq, a common weed known as 'Beshram' was introduced in India, as an ornamental plant. Surprisingly, except fiber length, other morphological characteristics like, cell wall thickness, lumen diameter, flexibility coefficient and wall fraction of I. cornea resemble with softwoods like, Pinus kesiya, and Picca abies. Cannabis sativa L., a common weed known as soft hemp consists of both bast fiber as well as core fiber. The unique morphological characteristics off. cameo like, cell wall thickness and flexibility coefficient, which resembles with softwoods along with long fibers of C. sativa, in which I. cornea deficits in a proper blend ratio, can be used in a better way for the development of high quality value added paper. The optimum kraft cooking conditions for I. cornea and C. sativa were: active alkali 16%, sulfidity 20%, temperature 165 degrees C, time (at temperature) 120 min and wood to liquor ratio of 1:4 for I. cornea and 1:3.5 for C. sativa. The screened pulp yield of I. cornea and C. sativa were found to be 49.3 and 54.3% at Kappa number of 29, respectively. An anthraquinone (AQ) dose of 0.1% increases the pulp yield to the tune of around 0.6% as well reduce the Kappa number to the tune of 22%. CEHH bleaching of C. saliva produces pulp brightness of 82% (Elrepho) at total chlorine demand of 5.07%. On contrary to this the I. Cornea kraft pulp at same chlorine demand produce a pulp with improved brightness of 85.4% (Elrepho). (C) 2008 Elsevier B.V. All rights reserved.