Injection molding

We found that sometimes when we peel off the print from the injected resin, ink remains on one side or sometimes on both sides. Why does this occur?

In the case of ink remaining on the substrate, adhesion to the injected resin is poor. When ink remains on the injected resin, the adhesion to the substrate is poor. This is delamination. When ink remains on both sides, adhesion to substrate and injected resin are good, but the cohesion of the ink layer is poor. This is a cohesion failure.

The printed layer peeled away from the injected resin. What should we do?

This may be due to a mismatch of ink, substrate and the resin. Please contact our representative.

We have always had good adhesion, but suddenly peeling has occurred. What should we do?

Ink attached so far but it suddenly peeled off. I don’t know what to do.
Please check the following.
(1) Film thickness of printed ink layer
Thinner binder layer tends to have weaker adhesion.
(2) Drying conditions for printed ink layer
If ink doesn’t dry sufficiently, the strength of the printed ink layer becomes weak and cohesive fracture will occur.
(3) Are there any additives such as defoamer contained in ink or binder?
If additive such as defoamer is added in ink, ink’s adhesion to resin tends to be weak.