Correlation of surface morphology of polyethylene films to ink adhesion and removal

The basic phenomenon of ink adhesion and removal has been studied by lookin g at the surface of polyethylene films that have been subjected to a cerami c bead impact ink-removal process where printed polyethylene films, zirconi um silicate beads, and water were agitated in a laboratory shaker. AFM imag es show that the polyethylene packaging film surfaces studied have a typica l morphology of polyethylene films crystallized under mechanical stress whi ch consists of rows, approximately 1 mum in width, of lamellar-like structu res. Upon impact of the ceramic beads on the polyethylene films, the surfac e is roughened and the surface rows appear to be deformed. FTIR data show t hat the surface crystallinity of the PE film decreases with the impact ink removal process. A deinking mechanism is proposed where the beads tear the ink film, abrade the surface and deform the polyethylene substrate.