Mixtures of Eucalyptus grandis x Eucalyptus urophylla and Pinus taeda wood chips for kraft pulp production by Lo-Solids® process

This paper is aiming to evaluate the possibility of cooking mixtures of Eucalyptus grandis x Eucalyptus urophylla and Pinus taeda for the production of kraft pulp with specific characteristics. Proportions of Pinus taeda from 10% to 50% were considered. The results indicated a downward trend in total yield and screened yield values, in pulp viscosity, in the hexenuronic acid content, in solubility in NaOH 5%, in the number of fibers per gram of pulp, in the drainability and strength and burst indices, with the increasing proportion of Pinus taeda in the pulps. As the proportion of Pinus taeda increased in the pulps an increase was noticed for the parameters total lignin content in the pulp, length and width of the fibers, coarseness and tear indices. In conclusion, the addition of up to 10% of Pinus taeda to Eucalyptus can increase pulp quality for the tear index and drainability parameters speeding up the paper machines and resulting in higher productivity. These mixtures also allow the production of tailor-made pulp and special papers.