Deinking of Digital Prints: Effect of Near-Neutral Deinking Chemistry on Deinkability

Abstract

This article demonstrates the effect of near-neutral deinking chemicals on the outcome of a deinking process. More specifically, we demonstrate that good deinkability of digital prints, i.e. liquid-electrophotographic (LEP), dry-electrophotographic and inkjet (IJ) prints, at the laboratory scale, can be achieved with effective near-neutral deinking chemistry that is based on readily available commercial chemicals. The deinking results meet or exceed the target levels, such as ink speck contamination (i.e. dirt area), ink elimination, filtrate darkening, color shade and luminosity, as defined by the European Recycling Paper Council’s deinking scorecard. It is noteworthy that the proposed chemistry has a prominent effect on reducing the dirt area of LEP print media and suppressing the filtrate darkening of dye-based IJ print media. Experimental results using the proposed deinking chemistry compare favorably to those obtained with alkaline deinking chemistry.