Effect of different types of fines on the properties of recycled chemical pulp

Abstract

The effect of fine content and quality on the recycled chemical pulps was studied. As fine content increased, the apparent sheet density linearly increased. The effect of fines from DIP (deinked pulp) on the apparent density of the sheets was the most prominent especially with the secondary fines. The addition of secondary fines obtained from HW-BKP ( hardwood-bleached kraft pulp) and DIP, and primary fines from DIP increased the tensile strength but decreased the light scattering coefficient after a critical point. The improvement of strength by secondary fines was caused by the different quality of fines, relatively larger specific area and higher WRVs (water retention values). While the primary fines of HW-BKP increased the light scattering coefficient but had little effects on the tensile strength. Porosity was rapidly decreased with the addition of secondary fines more than 30% regardless types of pulps. (C) 2011 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.