Quality Improvements Through
The UV Curing Process
1. UV ink can be purchased pre-mixed to a specified viscosity,
yielding consistent color from run to run as no mixing is
required by press operators. “UV ink viscosity formulations
developed in the last two years are very close to water-based
ink viscosity, allowing them to be poured into ink trays just
like water-based products. Additionally, with lower viscosity
UV ink, higher- line anilox in the range of 1000-1200 can
be used to allow greater dot control.” Since UV inks
are 100% solids, they are inherently stronger than water-based
inks, allowing less ink to attain the same color density as
well as provide enhanced color brightness.
2. Since UV inks do not evaporate in the ink trays, viscosity
and color remain consistent throughout the run. Additionally,
“water-based inks loose 50% of their volume through
evaporation during curing and also suffer high dot gain. Typically
a 2% dot on the plate will print at a 12% to 20% value, whereas
with UV the same plate with a 2% dot will print a value as
low as 5%.” Therefore, the printed product with UV more
closely matches the proof copy without significant compensation
in pre-press color separations to accommodate dot gain. This
yields much greater vignette control, particularly in the
highlight areas of the image, as dot gain is minimized. Also,
since there is no evaporative drying of UV inks, they do not
suffer from drying in the smallest dots on the plate or cause
“linting” (paper dust captured in the wet ink
and dried to the plate as the ink dries), both of which cause
defects in the printed material.
3. “UV inks have a much wider adhesion range than water-based
inks.” In many cases, UV primers are recommended to
overcome adherence issues with water-based inks, with the
primer applied at the first ink station. Water-based inks
adhere well to UV primers.
4. UV-printed and/or -coated materials have higher environmental
durability and are generally higher gloss with a higher degree
of color fastness than materials printed and/or coated with
water-based products.
5. UV coatings can accurately control slip angle for multi-wall
bag point of purchase displays.
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