Use of surfactants to remove solvent-based inks from plastic films

There is substantial economic and environmental incentive to remove the ink (deink) from heavily printed plastic films so that the plastic can be reused to produce clear films. In this study, polyethylene films printed with solvent-based ink were deinked using surfactants under a variety of conditions. Water without surfactant does not deink the solvent-based ink from plastic films over a pH range of 3 to 12. In common with earlier studies of water-based inks, it is found that solutions of cationic surfactants are the most effective for deinking of solvent-based ink but a pH of at least 11 is required. Presoaking of plastic film in aqueous solution of cationic surfactant increases the level of deinking. Limited studies performed with a pilot-size paper deinking apparatus on solvent-based ink removal indicates that the deinking of plastic film using surfactant solutions is technically feasible.