ABSTRACT
In de-inking flotation of wastepaper pulp, hydrophobic ink particles are collected by air bubbles and transported to a froth layer. Surface active chemicals control the surface tension of water and froth stability. Ethoxylated alcohols are among the popular surfactants selected for this application in US paper recycling plants [1-3]. The frothing potential of ethoxylated alcohol surfactants is well known, however, the effect of these chemicals on the properties of hydrophobic ink parti cles has not been examined. In this regard, systematic measurements of contact angles for ethoxylated alcohol solutions on hydrophobic toner and polyethylene surfaces were undertaken in this study using the sessile-drop technique.
