DEINKING OF NEW WATER-BASED GRAVURE INKS

In flotation deinking plants, the presence of a relatively small propo rtion of wastepapers printed with water-based flexographic inks leads to a significant loss of brightness of the deinked pulp. With the main thrust to reduce volatile organic compounds (VOC) in gravure printing , future formulations of water-based rotogravure inks are likely to re sult in problems similar to those caused by flexo inks in flotation de inking plants. The floatability of the new water-based gravure inks wa s investigated in three different systems: gravure ink dispersions fre e of fibres, dispersions with fibres and printed papers. The results i ndicated that water-based gravure inks behave similarly to flexo inks during flotation. They are easily washed in soft water but are not eas ily floated with conventional calcium soaps of fatty acids.