Poor ink adhesion is a common problem for
flexo printing. Here are some suggestions to solve the issue.
1) If the substrate does not match the ink,
it needs to be replaced. For plastic film materials, you can improve its
surface tension by corona treatment, or increase the coating to improve its
adhesion, in short, to ensure that its surface tension reaches 38 daine or
more.
2) In some cases, ink formulation causes poor
ink adhesion. If different batches of ink both cause this problem, then you can
pre-print a layer of priming coating before flexo printing the ink.
3) If the ink comes off easily on the
surface of the stamping foil, varnishing the material is a good way to protect
it.
(4) Excessive curing of the previous ink
color can also make poor adhesion between ink layers. It’s appropriate to
reduce the previous color group UV lamp curing power.
(5) Incomplete ink curing is one of factors.
Just find the cause and take appropriate measures.