Before proceeding with lamination of the printed sheet, it is necessary to check if the inks are completely dry.
This is very important in order to obtain a good adhesion of the film on the paper. In fact, the lamination of printed sheets with inks not yet perfectly dry is a frequent cause of delamination.
You may notice this in correspondence of creasing areas or other kinds of mechanical pressures. In fact, the film adhesive, not being able to "cling" to a stable and perfectly cross-linked layer, will show a decreased paper-film adhesion.
Therefore, it is essential to wait until the inks are perfectly dry, by paying particular attention to the case in which the sheets have been printed with high density (there is a lot of ink), dark colors or metallic inks.
There is also the case in which the sheets have a primer on the surface. Here you should check that the primer is suitable for lamination.
HOW TO PROCEED:
Since the print may only appear dry (while the innermost layers of the inks used may still not be perfectly crosslinked), it is necessary to use a more stringent method than simple scrubbing control.
Therefore, it is suggested to use mineral ray (or white spirit) and brush small portions of some printed sheets. If the ink is perfectly dry, there should be no streaks of colour.
Otherwise it is necessary to wait longer before proceeding with lamination.
We remind you that mineral ray is irritating and flammable. It is recommended consulting the safety data sheet provided by the producer.
Mag Data Spa
Stefano Galderisi