With rising environmental awareness, paper recycling becomes a more and more important issue also in marketing of printers and – accordingly – in the development of a printer. Still little is known about coherences. During the recycling process, the ink is separated from the paper fibers dissolved in water, and then it has to be removed from the aqueous suspension. For this separation, soap and air create bubbles that transport the ink to the surface of a flotation cell. This works easily with hydrophobic particles such as most offset and gravure inks. But this basic principle is also why most current aqueous inkjet inks are difficult to deink.INGEDE started communicating deinkability of digital prints in 2001 already to have this feature included as a development target. But it took until drupa 2008 until the major inkjet printer manufacturers realized that there is an issue. Still it is difficult to understand that the process to deink the mixture coming from household paper collection requires the process to work economically with the mixture rather than with single components.The underlying procedure for deinkability testing is INGEDE Method 11. Occasionally is being discussed whether it is relevant for all deinking processes, not only in Europe, also in the US. The procedure allows a solid assessment under standard conditions but is not meant to simulate every detail of a specific deinking plant. The method is a long time consensus within the paper industry designed to detect the challenges that a print product means for the basic deinking steps.
Axel Fischer, "Advances in Deinking and Deinkability of Inkjet Inks" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP26), 2010, pp 104 - 106, https://doi.org/10.2352/ISSN.2169-4451.2010.26.1.art00028_1