Low-surface-energy substrates like polypropylene and polyethylene resist ink adhesion. Pre-treatment changes the surface energy to make it amenable to bonding — or cross-linking — with the ink.
Plasma and corona
Electrical surface treatments. Plasma is favored in medical applications because it avoids byproducts like carbon residue. Corona works well for inline processes with easy maintenance.
Flame treatment
Uses propane or natural-gas combustion. Quick exposure polarizes material through oxidation, though heat may damage sensitive components.
Chemical priming
Manually applied primers chemically modify surfaces by removing contaminants and increasing surface energy, though they often contain volatile organic compounds.
Test before you commit
Successful treatment requires testing and careful setup. EPS offers technical support for testing inks and providing customer samples to verify print longevity requirements.