Effect of repulping variables on microscopic ink particles formed during deinking of toner printed paper

摘要

Deinking of non-impact printed papers has been a difficult task due to the differences in toner chemistry. Most deinking studies concentrate on the removal of visible ink particles (greater than 450 microns). However, microscopic ink particles though not visible, have an adverse effect on sheet brightness. Therefore, this work concentrates on the effective removal of microscopic ink particles. Repulping variables such as pH, repulping time and temperature, and RPM of the roto are varied to produce maximum amount of microscopic ink particles, so that their removal efficiency with a non ionic surfactant can be studied. The experiments are carried out for three different commercial toners. Ink particles are sought to be characterized by image analysis and confocal laser scanning microscopy.