After the PET film is dry-laminated, why is the ink always transferred to the inner film?

- Jan 09, 2021-

Reasons for ink transfer after dry compounding of PET film:

Since PET film has excellent barrier properties and strong anti-leakage properties, it is difficult for the solvent to penetrate, and the solvent absorption of the ink is poor. The binder (resin) of the plastic surface printing ink has a good affinity with the PET film, so printing on the PET film is stronger than the printing ink in the plastic composite.


In fact, the ink layer transfer of the printed PET film after compounding has nothing to do with the use of surface printing ink. Instead, the use of composite back printing ink is more prone to ink transfer.

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Solution:

Two points should be paid attention to during PET film printing and dry lamination:


1. The amount of glue applied during compounding must be small, and the solvent of compound glue shall be exhausted as much as possible when passing through the drying tunnel. (Always check whether the exhaust system of the drying tunnel is unblocked, and the compound hot drum temperature of the compound machine should not be lower than 70℃.


 2. Use as little ink as possible, and the ink should be dry (dry) to prevent false drying of the ink (especially when printing with chlorinated polypropylene composite plastic ink). If the printing speed of the printer cannot be turned on, and the effect of the drying box is poor, you can rewind the printed matter once, and blow air or leave it for some time during rewinding, and then recombine after the ink hardens. It is best to rewind and blow air to prevent the printing film from sticking).